CVE-2026-27737 (GCVE-0-2026-27737)
Vulnerability from cvelistv5 – Published: 2026-05-18 21:11 – Updated: 2026-05-19 12:11
VLAI
EPSS
VEX
Title
BigBlueButton has Stored XSS in bbb-playback replay
Summary
BigBlueButton is an open-source virtual classroom. In versions prior to 3.0.19, the recording playback (presentation format) was not sanitizing user's input in public chat. This allowed for a malicious actor to craft and carry out a targeted XSS attack, activated on anyone replaying the recording. This issue has been fixed 3.0.19.
Severity
6.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-19 12:11 UTC
CWE
- CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
5 references
| URL | Tags |
|---|---|
| https://github.com/bigbluebutton/bigbluebutton/se… | x_refsource_CONFIRM |
| https://github.com/bigbluebutton/bbb-playback/com… | x_refsource_MISC |
| https://github.com/bigbluebutton/bigbluebutton/co… | x_refsource_MISC |
| https://github.com/bigbluebutton/bigbluebutton/re… | x_refsource_MISC |
| https://github.com/blindsidenetworks/scalelite/re… | x_refsource_MISC |
Impacted products
3 products
| Vendor | Product | Version | |
|---|---|---|---|
| bigbluebutton | bigbluebutton |
Affected:
< 3.0.19
|
|
| blindsidenetworks | scalite |
Affected:
< 1.7.0
|
|
| bigbluebutton | bbb-playback |
Affected:
< 5.4.3
|
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},
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}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
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 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.
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.
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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.
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