01 Record
CVE-2026-91122
Discourse: Chat MessageBus delivers read-restricted messages to unauthorized users
HighPUBLISHEDCNA: GitHub_M
CNA base score8.7 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
02 Description
Discourse: Chat MessageBus delivers read-restricted messages to unauthorized users
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 0.26% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 17.6% of scored records. A rank, not a probability.
- NVD base score
- 8.7 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- NVD analysis status
- Deferred. NVD last modified this record on 2026-09-24.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-09-24 16:56Z1 MO AGO
- Last updated
- 2026-09-24 17:25Z1 MO AGO
- Reserved
- 2026-09-14
- Assigning CNA
- GitHub_M
- Record state
- PUBLISHED
- Severity
- High (CVSS 8.7)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- Weaknesses
- CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base
- Data version
- 5.2
- Document digest
- 02875f5704a7d490cf0aef780e1ea2fc7ee19895677702c419134f899068125c
05 Affected products
VendorProductVersionsPlatforms
discoursediscourse< 2026.8.0, >= 2026.7.0-latest, < 2026.7.2, >= 2026.6.0-latest, < 2026.6.3, >= 2026.1.0-latest, < 2026.1.8—
06 References
- github.comhttps://github.com/discourse/discourse/security/advisories/GHSA-8m44-f6g9-7cg7
- github.comhttps://github.com/discourse/discourse/pull/42882
- github.comhttps://github.com/discourse/discourse/commit/05d92b8749f68d2626cbe65ec7adde7562a0283d
- github.comhttps://github.com/discourse/discourse/commit/5674b3e6594825c28d2678e55057fd6802f11031
- github.comhttps://github.com/discourse/discourse/commit/c3993e318e172389be5c98455177876f1dd87dda
- github.comhttps://github.com/discourse/discourse/commit/d7126af3264b672d2201d84c18a37cb8627424a8