Vulnerability-Lookup

GHSA-MVMF-94V6-879G

Vulnerability from github – Published: 2026-06-30 15:30 – Updated: 2026-09-30 23:52

Summary

fzf vulnerable to denial of service through quadratic HTTP request-body accumulation

Details

fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n²)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single‑threaded HTTP server, blocking all other clients and resulting in denial of service.

This issue was fixed in version 0.73.1.

Severity

5.7 (Medium)


                  
                    CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/junegunn/fzf"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.73.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-53433"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-407"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-30T23:52:48Z",
    "nvd_published_at": "2026-06-30T13:19:13Z",
    "severity": "MODERATE"
  },
  "details": "fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n\u00b2)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single\u2011threaded HTTP server, blocking all other clients and resulting in denial of service.\n\nThis issue was fixed in version 0.73.1.",
  "id": "GHSA-mvmf-94v6-879g",
  "modified": "2026-09-30T23:52:48Z",
  "published": "2026-06-30T15:30:44Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53433"
    },
    {
      "type": "WEB",
      "url": "https://github.com/junegunn/fzf/commit/7963a2c6586c0b9eaa89b8995de8f0e08cf8a4ce"
    },
    {
      "type": "WEB",
      "url": "https://cert.pl/en/posts/2026/06/CVE-2026-53432"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/junegunn/fzf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/junegunn/fzf/releases/tag/v0.73.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "fzf vulnerable to denial of service through quadratic HTTP request-body accumulation"
}

CVE-2026-53433 (GCVE-0-2026-53433)

Vulnerability from cvelistv5 – Published: 2026-06-30 12:01 – Updated: 2026-06-30 13:32 X_Open Source

Title

Denial of Service in fzf

Summary

Severity

5.7 (Medium)


                        
                          CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-30 13:32 UTC

CWE

CWE-407 - Inefficient Algorithmic Complexity

Assigner

CERT-PL ENISA root Scorecard

References

3 references

URL	Tags
https://cert.pl/en/posts/2026/06/CVE-2026-53432	third-party-advisory
https://github.com/junegunn/fzf	product
https://github.com/junegunn/fzf/commit/7963a2c658…	issue-tracking

Impacted products

1 product

Vendor	Product	Version
fzf	fzf	Affected: 0 , < 0.73.1 (semver)

Date Public

2026-06-30 12:01

Credits

Michał Majchrowicz (AFINE Team) Marcin Wyczechowski (AFINE Team)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-53433",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-30T13:32:32.210950Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-30T13:32:52.251Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "fzf",
          "programFiles": [
            "src/server.go"
          ],
          "repo": "https://github.com/junegunn/fzf",
          "vendor": "fzf",
          "versions": [
            {
              "lessThan": "0.73.1",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Micha\u0142 Majchrowicz (AFINE Team)"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "Marcin Wyczechowski (AFINE Team)"
        }
      ],
      "datePublic": "2026-06-30T12:01:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen \u003cspan style=\"background-color: rgba(221, 223, 228, 0.04);\"\u003emode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n\u00b2)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.\u003c/span\u003eThis allows a single malicious request to monopolize the single\u2011threaded HTTP server, blocking all other clients and resulting in denial of service.\u003cbr\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e\u003cbr\u003e\u003c/span\u003e\u003c/span\u003eThis issue was fixed in version 0.73.1.\u003cbr\u003e"
            }
          ],
          "value": "fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the --listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n\u00b2)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single\u2011threaded HTTP server, blocking all other clients and resulting in denial of service.\n\nThis issue was fixed in version 0.73.1."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "LOCAL",
            "baseScore": 5.7,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-407",
              "description": "CWE-407 Inefficient Algorithmic Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-30T12:01:14.407Z",
        "orgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
        "shortName": "CERT-PL"
      },
      "references": [
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://cert.pl/en/posts/2026/06/CVE-2026-53432"
        },
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/junegunn/fzf"
        },
        {
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/junegunn/fzf/commit/7963a2c6586c0b9eaa89b8995de8f0e08cf8a4ce"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "tags": [
        "x_open-source"
      ],
      "title": "Denial of Service in fzf",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "4bb8329e-dd38-46c1-aafb-9bf32bcb93c6",
    "assignerShortName": "CERT-PL",
    "cveId": "CVE-2026-53433",
    "datePublished": "2026-06-30T12:01:14.407Z",
    "dateReserved": "2026-06-09T11:41:37.126Z",
    "dateUpdated": "2026-06-30T13:32:52.251Z",
    "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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-MVMF-94V6-879G

CVE-2026-53433 (GCVE-0-2026-53433)

Tags

Sightings

Nomenclature

Related by attack behaviour