CVE-2026-91859 MISP Access Log Entry Overwritten by Error Controller's Second beforeFilter Pass
Attackers can corrupt MISP access logs by triggering exceptions, causing incorrect metrics to overwrite valid entries, impacting audit integrity.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-91859?
CVE-2026-91859 is a medium-severity vulnerability in MISP, published on 15 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Affected versions of MISP can record incorrect access-log data for requests that terminate in an exception.
Because CakeErrorController extends AppController, exception rendering runs the application startup path a second time. As a result, __accessMonitor() calls AccessLog::logRequest() twice for one HTTP request. The second deferred writer measures the error-controller execution instead of the original request and can overwrite the row created by the first pass. The corrupted fields include request duration, SQL query count, memory usage, and potentially the recorded query log.
The bug was masked because the same model instance retained the ID of the first saved row, causing the later save to issue an UPDATE rather than insert an obvious duplicate row.
Version affected: ≤2.5.45
Which versions are affected by CVE-2026-91859?
How do I fix CVE-2026-91859?
No fix has been published for CVE-2026-91859 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-91859 being exploited?
There is no known exploitation of CVE-2026-91859 in the wild and no public exploit code.
Sources
Also known as GHSA-qx5f-75hg-mf2c.