PatchTheCVECVE-2026-85238: MISP contains a session fixation vulnerability in the CustomAuth authentication (a custom configuration) flow
CVE-2026-85238 is a medium-severity flaw (CVSS 6.8) affecting misp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
MISP contains a session fixation vulnerability in the CustomAuth authentication (a custom configuration) flow. When a user was successfully authenticated through CustomAuth, MISP stored the authenticated user identity in the existing session without first rotating the session identifier. As a result, if an attacker can cause a victim to use a session identifier known to the attacker before authentication, that same session identifier remains va
Why this priority
- No elevated risk signals yet
A fixed release or distro patch exists.
Risk facts
| CVSS score | 6.8 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 73%) |
| CISA exploited list | No |
| Weakness | CWE-384 |
| Published | 2026-09-03 |
| Last modified | 2026-09-11 |
Last updated 2026-09-11 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-85238?
misp: upgrade to newer than 2.5.45. Exact commands for each OS are on this page.
Is CVE-2026-85238 being exploited?
CVE-2026-85238 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-85238 affect?
CVE-2026-85238 affects misp. Severity is medium (CVSS 6.8). MISP contains a session fixation vulnerability in the CustomAuth authentication (a custom configuration) flow. When a user was successfully authenticated through CustomAuth, MISP stored the authenticated user identity in the existing sessio
How urgent is CVE-2026-85238?
Priority 30/100. No elevated risk signals yet.
Related CVEs
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- CVE-2026-85237 HIGH 8.1 UPGRADE A vulnerability in MISP's email-based one-time password (OTP) authentication flow allowed an attacker to perfo
- CVE-2026-85236 HIGH 8.8 UPGRADE A cross-site request forgery (CSRF) vulnerability existed in the cullEmptyEvents action of MISP
- CVE-2026-85216 CRITICAL 9.8 UPGRADE MISP contains an authentication bypass vulnerability in its LDAP and LinOTP authentication components due to i
- CVE-2026-85221 CRITICAL 9.1 UPGRADE MISP contains an improper TLS certificate validation vulnerability in CurlClient