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Fencer Intel
high 7.5

CVE-2026-91947 json

FreeRDP Server before 3.31.0 Use-After-Free via DRDYNVC

published 2mo ago modified 8d ago also EUVD-2026-78804 , GHSA-6mpx-c8rj-whj5

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository FreeRDP/FreeRDP. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

FreeRDP server versions before 3.31.0 contain a use-after-free vulnerability in the DRDYNVC parser that dereferences a channel pointer after releasing the synchronization lock. Authenticated clients can race AUDIN channel closure messages against DRDYNVC data parsing to trigger heap-use-after-free when accessing freed channel objects.

Patch / fix

  • FreeRDP FreeRDP 3.31.0
  • freerdp3 Debian 14 3.31.0+dfsg-1

debian advisories DEBIAN-CVE-2026-91947

  • freerdp3 Ubuntu 24.04 LTS 3.31.0+dfsg-0ubuntu0.24.04.1
  • freerdp3 Ubuntu 26.04 LTS 3.31.0+dfsg-0ubuntu0.26.04.1

ubuntu advisories UBUNTU-CVE-2026-91947

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • freerdp RHEL 10.2 2:3.10.3-12.el10_2.14
  • libwinpr RHEL 10.2 2:3.10.3-12.el10_2.14
  • freerdp-libs RHEL 10.2 2:3.10.3-12.el10_2.14
  • freerdp-server RHEL 10.2 2:3.10.3-12.el10_2.14

red hat advisories RHSA-2026:75570

  • freerdp AlmaLinux 10 2:3.10.3-12.el10_2.14
  • libwinpr AlmaLinux 10 2:3.10.3-12.el10_2.14
  • freerdp-libs AlmaLinux 10 2:3.10.3-12.el10_2.14
  • freerdp-server AlmaLinux 10 2:3.10.3-12.el10_2.14

almalinux advisories ALSA-2026:75570

  • freerdp Rocky Linux 10 2:3.10.3-12.el10_2.14

rocky linux advisories RLSA-2026:75570

Is CVE-2026-91947 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-91947 updated cvss 7.5

FreeRDP: FreeRDP: Use-after-free vulnerability in DRDYNVC parser leads to memory corruption

  • Red Hat Enterprise Linux 9 freerdp, libwinpr, freerdp-libs
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AppStream (v. 10) freerdp 3.32.2-1.el10_3, libwinpr 3.32.2-1.el10_3, freerdp 3.10.3-12.el10_2.14, freerdp-libs 3.32.2-1.el10_3, libwinpr 3.10.3-12.el10_2.14, freerdp-libs 3.10.3-12.el10_2.14 Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) freerdp-server 3.32.2-1.el10_3, freerdp-server 3.10.3-12.el10_2.14
    fixed: vendor fix RHSA-2026:75570
  • Red Hat Enterprise Linux Server (v. 7 ELS) freerdp 2.1.1-5.el7_9.14, libwinpr 2.1.1-5.el7_9.14, freerdp-libs 2.1.1-5.el7_9.14 Red Hat Enterprise Linux Server Optional (v. 7 ELS) freerdp-devel 2.1.1-5.el7_9.14, libwinpr-devel 2.1.1-5.el7_9.14, freerdp-debuginfo 2.1.1-5.el7_9.14
    fixed: vendor fix RHSA-2026:93559
  • Red Hat Enterprise Linux 6 freerdp, freerdp-libs, freerdp-plugins
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 8 freerdp, libwinpr, freerdp-libs
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6mpx-c8rj-whj5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 7.7 CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 4.0 7.7 CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • FreeRDP FreeRDP

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of FreeRDP/FreeRDP published their own advisory on GitHub. Reviewed sources take precedence over it.