CVE-2026-91945 FreeRDP before 3.31.0 Out-of-bounds Read via Smartcard ATR
Authenticated RDP clients can trigger an out-of-bounds read in FreeRDP smartcard decoders, causing process termination and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-91945?
CVE-2026-91945 is a high-severity memory corruption vulnerability in Freerdp Freerdp, published on 15 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
FreeRDP versions before 3.31.0 contain an out-of-bounds read vulnerability in smartcard response decoders that fail to validate ATR length fields against fixed inline arrays. Authenticated RDP clients can send oversized ATR lengths in PAKID_CORE_DEVICE_IOCOMPLETION responses to trigger reads past stack or heap objects, causing process termination.
Weakness: CWE-125
Which versions are affected by CVE-2026-91945?
It affects 1 product.
Products include Freerdp Freerdp.
How do I fix CVE-2026-91945?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-91945 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-91945 exists.
Other vulnerabilities in Freerdp Freerdp
- CVE-2021-37594 Other in n/a
- CVE-2021-37595 Other in n/a
- CVE-2026-67305 FreeRDP Windows Client before 3.29.0 Heap Buffer Overflow via Cliprdr
- CVE-2026-66402 FreeRDP before 3.29.0 TLS Certificate Identity Validation Bypass
- CVE-2026-67289 FreeRDP before 3.29.0 HTTP Proxy Request Injection via Redirection
Sources
Also known as DEBIAN-CVE-2026-91945, GHSA-q65v-4w7q-hx3r, GHSA-w579-5rqc-5mqh, UBUNTU-CVE-2026-91945.