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EUVD-2026-348396

European Vulnerability Database identifier assigned by ENISA

Reserved

2026-10-02 08:19

Assigner

ENISA

Alias of

a CVE record, shown under related vulnerabilities. This identifier carries no description, severity or references of its own: they belong to that CVE.

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{
  "assigner": "ENISA",
  "date_reserved": "2026-10-02T08:19:38.667915+00:00",
  "id": "EUVD-2026-348396"
}

CVE-2026-64091 (GCVE-0-2026-64091)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:40 – Updated: 2026-08-05 12:39

Title

batman-adv: tt: fix TOCTOU race for reported vlans

Summary

In the Linux kernel, the following vulnerability has been resolved: batman-adv: tt: fix TOCTOU race for reported vlans The local TT based TVLV is generated by first checking the number of VLANs which have at least one TT entry. A new buffer with the correct size for the VLANs is then allocated. Only then, the list of VLANs s used to fill the VLAN entries in the buffer. During this time, the meshif_vlan_list_lock is held. But the actual number of TT entries of each VLAN can still increase during this time - just not the number of VLANs in the list. But the prefilter used in the buffer size calculation might still cause an increase of the number of VLANs which need to be stored. Simply because a VLAN might now suddenly have at least one entry when it had none in the pre-alloc check - and then needs to occupy space which was not allocated. It is better to overestimate the buffer size at the beginning and then fill the buffer only with the VLANs which are not empty.

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root Scorecard

References

8 references

URL	Tags
https://git.kernel.org/stable/c/e4236bf3ec8d6bb15…
https://git.kernel.org/stable/c/724a8eb4155669797…
https://git.kernel.org/stable/c/211ea59988e1cba43…
https://git.kernel.org/stable/c/65a1e67339aa8c95a…
https://git.kernel.org/stable/c/b4d4efd4e351593c8…
https://git.kernel.org/stable/c/4cc85aec8d3c9ab4d…
https://git.kernel.org/stable/c/9a9c859457bc440a5…
https://git.kernel.org/stable/c/94d27005016be15ff…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 16116dac23396e73c01eeee97b102e4833a4b205 , < e4236bf3ec8d6bb15d0d8d825dcf9933a7d6666b (git) Affected: 16116dac23396e73c01eeee97b102e4833a4b205 , < 724a8eb4155669797c96b70d70e354284ae3b5a8 (git) Affected: 16116dac23396e73c01eeee97b102e4833a4b205 , < 211ea59988e1cba43cb0367ad65d379b56f9c3bd (git) Affected: 16116dac23396e73c01eeee97b102e4833a4b205 , < 65a1e67339aa8c95ac544b796946af388930ee23 (git) Affected: 16116dac23396e73c01eeee97b102e4833a4b205 , < b4d4efd4e351593c81e9293d4b4408d244fa5ee7 (git) Affected: 16116dac23396e73c01eeee97b102e4833a4b205 , < 4cc85aec8d3c9ab4dc716dc9f1ed36fca16b227f (git) Affected: 16116dac23396e73c01eeee97b102e4833a4b205 , < 9a9c859457bc440a55773e01ff18b1bb5bab6836 (git) Affected: 16116dac23396e73c01eeee97b102e4833a4b205 , < 94d27005016be15ffc638b2ecbc4d58805ad7b48 (git) Affected: 3134c5a32810c510f1f447c135cec346acbb71c3 (git) Affected: e861e03a1b5b615ad1b57b1802b17e260eedccfe (git) Affected: 0b81edc8818903c64c4d121bc51cd5825be8cc67 (git) Affected: 90ae6475b1753f0c1a4c66034b5666de3189fac8 (git) Affected: 3.16.60 , < 3.17 (semver) Affected: 4.4.217 , < 4.5 (semver) Affected: 4.9.217 , < 4.10 (semver) Affected: 4.14.174 , < 4.15 (semver)
Linux	Linux	Affected: 4.17 Unaffected: 0 , < 4.17 (semver) Unaffected: 5.10.259 , ≤ 5.10.* (semver) Unaffected: 5.15.210 , ≤ 5.15.* (semver) Unaffected: 6.1.176 , ≤ 6.1.* (semver) Unaffected: 6.6.143 , ≤ 6.6.* (semver) Unaffected: 6.12.93 , ≤ 6.12.* (semver) Unaffected: 6.18.34 , ≤ 6.18.* (semver) Unaffected: 7.0.11 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/batman-adv/translation-table.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e4236bf3ec8d6bb15d0d8d825dcf9933a7d6666b",
              "status": "affected",
              "version": "16116dac23396e73c01eeee97b102e4833a4b205",
              "versionType": "git"
            },
            {
              "lessThan": "724a8eb4155669797c96b70d70e354284ae3b5a8",
              "status": "affected",
              "version": "16116dac23396e73c01eeee97b102e4833a4b205",
              "versionType": "git"
            },
            {
              "lessThan": "211ea59988e1cba43cb0367ad65d379b56f9c3bd",
              "status": "affected",
              "version": "16116dac23396e73c01eeee97b102e4833a4b205",
              "versionType": "git"
            },
            {
              "lessThan": "65a1e67339aa8c95ac544b796946af388930ee23",
              "status": "affected",
              "version": "16116dac23396e73c01eeee97b102e4833a4b205",
              "versionType": "git"
            },
            {
              "lessThan": "b4d4efd4e351593c81e9293d4b4408d244fa5ee7",
              "status": "affected",
              "version": "16116dac23396e73c01eeee97b102e4833a4b205",
              "versionType": "git"
            },
            {
              "lessThan": "4cc85aec8d3c9ab4dc716dc9f1ed36fca16b227f",
              "status": "affected",
              "version": "16116dac23396e73c01eeee97b102e4833a4b205",
              "versionType": "git"
            },
            {
              "lessThan": "9a9c859457bc440a55773e01ff18b1bb5bab6836",
              "status": "affected",
              "version": "16116dac23396e73c01eeee97b102e4833a4b205",
              "versionType": "git"
            },
            {
              "lessThan": "94d27005016be15ffc638b2ecbc4d58805ad7b48",
              "status": "affected",
              "version": "16116dac23396e73c01eeee97b102e4833a4b205",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "3134c5a32810c510f1f447c135cec346acbb71c3",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e861e03a1b5b615ad1b57b1802b17e260eedccfe",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "0b81edc8818903c64c4d121bc51cd5825be8cc67",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "90ae6475b1753f0c1a4c66034b5666de3189fac8",
              "versionType": "git"
            },
            {
              "lessThan": "3.17",
              "status": "affected",
              "version": "3.16.60",
              "versionType": "semver"
            },
            {
              "lessThan": "4.5",
              "status": "affected",
              "version": "4.4.217",
              "versionType": "semver"
            },
            {
              "lessThan": "4.10",
              "status": "affected",
              "version": "4.9.217",
              "versionType": "semver"
            },
            {
              "lessThan": "4.15",
              "status": "affected",
              "version": "4.14.174",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/batman-adv/translation-table.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.17"
            },
            {
              "lessThan": "4.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.259",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.259",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.210",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.176",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.143",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.93",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.34",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.11",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "4.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "3.16.60",
                  "vulnerable": true
                },
                {
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                  "versionStartIncluding": "4.4.217",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "4.9.217",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "4.14.174",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: tt: fix TOCTOU race for reported vlans\n\nThe local TT based TVLV is generated by first checking the number of VLANs\nwhich have at least one TT entry. A new buffer with the correct size for\nthe VLANs is then allocated. Only then, the list of VLANs s used to fill\nthe VLAN entries in the buffer. During this time, the meshif_vlan_list_lock\nis held. But the actual number of TT entries of each VLAN can still\nincrease during this time - just not the number of VLANs in the list.\n\nBut the prefilter used in the buffer size calculation might still cause an\nincrease of the number of VLANs which need to be stored. Simply because a\nVLAN might now suddenly have at least one entry when it had none in the\npre-alloc check - and then needs to occupy space which was not allocated.\n\nIt is better to overestimate the buffer size at the beginning and then fill\nthe buffer only with the VLANs which are not empty."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The bug is hit in `batadv_tt_prepare_tvlv_local_data()` when building TT TVLVs for OGM updates or TT_RESPONSE replies. A remote mesh peer can trigger the response path by sending unicast TVLV TT_REQUEST packets (`batadv_recv_unicast_tvlv` \u2192 `batadv_tt_tvlv_unicast_handler_v1` \u2192 `batadv_send_my_tt_response`) and can race the OGM commit path by flooding mesh traffic that registers new clients via `batadv_tt_local_add()`.\nAC:L - The attacker controls both sides of the TOCTOU race by concurrently sending TT_REQUEST packets and traffic that adds TT entries to VLANs that were empty during the size calculation. No victim-specific memory layout or rare timing outside the attacker\u0027s control is required.\nPR:N - Exploitation requires only participation in an active batman-adv mesh as an unauthenticated remote peer sending protocol packets. No local Linux credentials, capabilities, or netlink/rtnl admin rights on the victim host are needed.\nUI:N - The vulnerability is triggered entirely by attacker-sent mesh protocol packets and concurrent traffic processing; no victim user action such as mounting a filesystem or opening a file is required.\nS:U - The out-of-bounds write corrupts kernel heap memory within the same kernel security boundary. This is standard in-kernel memory corruption, not a cross-boundary escape such as VM guest-to-host or IOMMU bypass.\nC:H - The TOCTOU causes undersized `kmalloc()` allocation followed by out-of-bounds writes of `batadv_tvlv_tt_vlan_data` structures (8 bytes each) and misplacement of the TT changes region, with subsequent `memcpy()` of change entries writing further past the buffer end. Heap corruption of this kind can be leveraged for arbitrary kernel memory disclosure.\nI:H - Writing VLAN headers and TT change records beyond the allocated buffer is a kernel heap buffer overflow. With heap grooming this class of corruption is exploitable for arbitrary kernel memory writes and potential privilege escalation.\nA:H - Heap corruption from the out-of-bounds writes can cause immediate kernel oops/panic from corrupting adjacent slab objects or allocator metadata, and is independently a high availability impact even before successful exploitation."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:39:07.214Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/e4236bf3ec8d6bb15d0d8d825dcf9933a7d6666b"
        },
        {
          "url": "https://git.kernel.org/stable/c/724a8eb4155669797c96b70d70e354284ae3b5a8"
        },
        {
          "url": "https://git.kernel.org/stable/c/211ea59988e1cba43cb0367ad65d379b56f9c3bd"
        },
        {
          "url": "https://git.kernel.org/stable/c/65a1e67339aa8c95ac544b796946af388930ee23"
        },
        {
          "url": "https://git.kernel.org/stable/c/b4d4efd4e351593c81e9293d4b4408d244fa5ee7"
        },
        {
          "url": "https://git.kernel.org/stable/c/4cc85aec8d3c9ab4dc716dc9f1ed36fca16b227f"
        },
        {
          "url": "https://git.kernel.org/stable/c/9a9c859457bc440a55773e01ff18b1bb5bab6836"
        },
        {
          "url": "https://git.kernel.org/stable/c/94d27005016be15ffc638b2ecbc4d58805ad7b48"
        }
      ],
      "title": "batman-adv: tt: fix TOCTOU race for reported vlans",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64091",
    "datePublished": "2026-07-19T15:40:00.030Z",
    "dateReserved": "2026-07-19T07:54:57.032Z",
    "dateUpdated": "2026-08-05T12:39:07.214Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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EUVD-2026-348396

CVE-2026-64091 (GCVE-0-2026-64091)

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Nomenclature

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