synced JUST NOW
01 Record

CVE-2026-91134

Discourse: Block post iframes whose encoded userinfo bypasses the allowed_iframes allowlist

MediumPUBLISHEDCNA: GitHub_M
CNA base score5.4 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
View raw JSON

02 Description

Discourse: Block post iframes whose encoded userinfo bypasses the allowed_iframes allowlist

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 ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.21% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 11.8% of scored records. A rank, not a probability.
NVD base score
5.4 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
NVD analysis status
Deferred. NVD last modified this record on 2026-09-29.
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 16:51Z1 MO AGO
Last updated
2026-09-29 02:56Z1 MO AGO
Reserved
2026-09-14
Assigning CNA
GitHub_M
Record state
PUBLISHED
Severity
Medium (CVSS 5.4)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Weaknesses
  • CWE-20Improper Input ValidationClass
Data version
5.2
Document digest
227c37534411dfd51ac3bd86f8340ce3bd0cceec9a5b9b66455cb689ef2c86c8

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