PatchTheCVECVE-2026-66401: FreeRDP before 3.29.0 contains an out-of-bounds heap read vulnerability in the UVC H.264 extension-unit parser
CVE-2026-66401 is a low-severity flaw (CVSS 2.1) affecting freerdp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
FreeRDP before 3.29.0 contains an out-of-bounds heap read vulnerability in the UVC H.264 extension-unit parser that fails to validate descriptor length before accessing the GUID field. A local attacker with a malicious USB video camera can trigger a heap read beyond allocated bounds during camera stream setup, causing denial of service.
Why this priority
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 2.1 (Low) |
| Attack vector | Physical |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | Required |
| EPSS exploit chance | 0.2% (top 90%) |
| CISA exploited list | No |
| Weakness | CWE-125 |
| Published | 2026-08-01 |
| Last modified | 2026-09-03 |
Last updated 2026-09-03 · 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-2026-66401?
freerdp: upgrade to 3.29.0. Exact commands for each OS are on this page.
Is CVE-2026-66401 being exploited?
CVE-2026-66401 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-2026-66401 affect?
CVE-2026-66401 affects freerdp. Severity is low (CVSS 2.1). FreeRDP before 3.29.0 contains an out-of-bounds heap read vulnerability in the UVC H.264 extension-unit parser that fails to validate descriptor length before accessing the GUID field. A local attacker with a malicious USB video camera can
How urgent is CVE-2026-66401?
Priority 15/100. Public exploit reference
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