CVE-2026-91948

EUVD-2026-78805
FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in server-side static virtual channel handling when CHANNEL_OPTION_SHOW_PROTOCOL is enabled. Authenticated clients can queue oversized channel messages that cause buffer underflow and corrupt heap memory including live pointers, potentially enabling code execution.
Wrap or Wraparound
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
VulnCheckCNA
7.5 HIGH
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
freerdpfreerdp
3.28.0 ≤
𝑥
< 3.31.0
CNA
Debian logo
Debian Releases
Debian Product
Codename
freerdp2
bookworm
2.11.7+dfsg1-6~deb12u1
fixed
freerdp3
forky
3.31.1+dfsg-1
fixed
sid
3.31.1+dfsg-1
fixed
trixie
3.15.0+dfsg-2.1+deb13u3
fixed
Common Weakness Enumeration
References
https://github.com/FreeRDP/FreeRDP/commit/40d9202cd95551600c07437ce6bd5ecd7d31e57b
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9jcm-x588-gh26
https://www.vulncheck.com/advisories/freerdp-before-3.31.0-out-of-bounds-write-via-show-protocol
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9jcm-x588-gh26