CVE-2026-91857
MISP: State-changing actions accessible via GET request enabling CSRF
02 Description
MISP: State-changing actions accessible via GET request enabling CSRF
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.
- EPSS probability
- 0.21% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 11.6% of scored records. A rank, not a probability.
- NVD base score
- 5.3 (CVSS v4.0), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- NVD analysis status
- Deferred. NVD last modified this record on 2026-09-16.
- 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
- 2026-09-15 09:14Z1 MO AGO
- Last updated
- 2026-09-15 13:19Z1 MO AGO
- Reserved
- 2026-09-15
- Assigning CNA
- CIRCL
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 5.3)
- CNA CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
- Weaknesses
- CWE-352Cross-Site Request Forgery (CSRF)Compound
- Data version
- 5.2
- Document digest
- 15183b02247a73e6125144a46fea9a09a0f69037e66115f91567d64f0a4eb825
05 Affected products
06 References
- github.comSecurity patchhttps://github.com/MISP/MISP/commit/b4a5486b5
07 Remediation
The vulnerability is remediated by restricting all four state-changing actions to accept only POST requests via the CakePHP allowMethod() guard. Additionally, the client-side JavaScript for purgeUnusedPictures is updated to issue a POST request with the page's CSRF token in the X-CSRF-Token header, and a beforeFilter() hook is added to EventReportsController to configure header-only CSRF token validation for that specific action, since it is invoked via hand-built AJAX rather than a rendered form.