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Fencer Intel
medium 6.5

CVE-2026-91963 json

FreeRDP 2.0.0 through 3.30.0 Uninitialized Heap Memory Disclosure via urbdrc

published 2mo ago modified last mo. also EUVD-2026-78639 , GHSA-hw7p-5h2r-83gq

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
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 52%
public exploits
0
none known

Summary

FreeRDP versions before 3.31.0 contain an uninitialized heap memory disclosure vulnerability in the urbdrc USB redirection channel. A malicious RDP server can induce failing USB transfers to read uninitialized heap memory from the client, defeating ASLR and enabling remote code execution when chained with memory corruption vulnerabilities.

Patch / fix

  • FreeRDP FreeRDP 3.0.0, 3.31.0
  • freerdp3 Debian 14 3.31.0+dfsg-1

debian advisories DEBIAN-CVE-2026-91963

  • 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-2026-91963

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 9 2:2.11.7-7.el9_8.8
  • libwinpr RHEL 9 2:2.11.7-7.el9_8.8
  • freerdp-libs RHEL 9 2:2.11.7-7.el9_8.8
  • freerdp RHEL 8 2:2.11.7-14.el8_10
  • libwinpr RHEL 8 2:2.11.7-14.el8_10
  • freerdp-libs RHEL 8 2:2.11.7-14.el8_10
  • freerdp RHEL 10.2 2:3.10.3-12.el10_2.14
  • libwinpr RHEL 10.2 2:3.10.3-12.el10_2.14

red hat advisories RHSA-2026:76755RHSA-2026:76747RHSA-2026:75570

  • freerdp AlmaLinux 8 2:2.11.7-14.el8_10
  • libwinpr AlmaLinux 8 2:2.11.7-14.el8_10
  • freerdp-libs AlmaLinux 8 2:2.11.7-14.el8_10
  • freerdp AlmaLinux 9 2:2.11.7-7.el9_8.8
  • libwinpr AlmaLinux 9 2:2.11.7-7.el9_8.8
  • freerdp-libs AlmaLinux 9 2:2.11.7-7.el9_8.8
  • freerdp AlmaLinux 10 2:3.10.3-12.el10_2.14
  • libwinpr AlmaLinux 10 2:3.10.3-12.el10_2.14

almalinux advisories ALSA-2026:76747ALSA-2026:76755ALSA-2026:75570

  • freerdp Rocky Linux 9 2:2.11.7-7.el9_8.8
  • freerdp Rocky Linux 8 2:2.11.7-14.el8_10
  • freerdp Rocky Linux 10 2:3.10.3-12.el10_2.14

rocky linux advisories RLSA-2026:76755RLSA-2026:76747RLSA-2026:75570

Is CVE-2026-91963 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.

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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-2026-91963 updated cvss 8.8

FreeRDP: FreeRDP: Remote code execution via uninitialized heap memory disclosure

  • Red Hat Enterprise Linux 6 freerdp, freerdp-libs, freerdp-plugins
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder EUS (v.9.6) freerdp-devel 2.11.7-1.el9_6.15, libwinpr-devel 2.11.7-1.el9_6.15, freerdp-debuginfo 2.11.7-1.el9_6.15, libwinpr-debuginfo 2.11.7-1.el9_6.15, freerdp-debugsource 2.11.7-1.el9_6.15, freerdp-libs-debuginfo 2.11.7-1.el9_6.15
    fixed: vendor fix RHSA-2026:99035
  • Red Hat Enterprise Linux AppStream (v. 8) freerdp 2.11.7-14.el8_10, libwinpr 2.11.7-14.el8_10, freerdp-libs 2.11.7-14.el8_10
    fixed: vendor fix RHSA-2026:76747
  • Red Hat Enterprise Linux AppStream (v. 9) freerdp 2.11.7-7.el9_8.8, freerdp 2.11.7-13.el9_9.2, libwinpr 2.11.7-7.el9_8.8, libwinpr 2.11.7-13.el9_9.2, freerdp-libs 2.11.7-7.el9_8.8, freerdp-libs 2.11.7-13.el9_9.2
    fixed: vendor fix RHSA-2026:76755
  • 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
    fixed: vendor fix RHSA-2026:75570
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) freerdp 2.2.0-14.el8_4.5, libwinpr 2.2.0-14.el8_4.5, freerdp-libs 2.2.0-14.el8_4.5
    fixed: vendor fix RHSA-2026:93538
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) freerdp 2.2.0-7.el8_6.14, libwinpr 2.2.0-7.el8_6.14, freerdp-libs 2.2.0-7.el8_6.14
    fixed: vendor fix RHSA-2026:93549
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) freerdp 2.2.0-12.el8_8.13, libwinpr 2.2.0-12.el8_8.13, freerdp-libs 2.2.0-12.el8_8.13
    fixed: vendor fix RHSA-2026:93537
show 9 more
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) freerdp 2.11.2-1.el9_4.13, libwinpr 2.11.2-1.el9_4.13, freerdp-libs 2.11.2-1.el9_4.13
    fixed: vendor fix RHSA-2026:99034
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) freerdp 2.11.7-1.el9_6.15, libwinpr 2.11.7-1.el9_6.15, freerdp-libs 2.11.7-1.el9_6.15
    fixed: vendor fix RHSA-2026:99035
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) freerdp 2.2.0-14.el8_4.5, libwinpr 2.2.0-14.el8_4.5, freerdp-libs 2.2.0-14.el8_4.5
    fixed: vendor fix RHSA-2026:93538
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) freerdp 2.2.0-7.el8_6.14, libwinpr 2.2.0-7.el8_6.14, freerdp-libs 2.2.0-7.el8_6.14
    fixed: vendor fix RHSA-2026:93549
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) freerdp 2.2.0-12.el8_8.13, libwinpr 2.2.0-12.el8_8.13, freerdp-libs 2.2.0-12.el8_8.13
    fixed: vendor fix RHSA-2026:93537
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) freerdp-devel 2.11.7-7.el9_8.8, freerdp-devel 2.11.7-13.el9_9.2, libwinpr-devel 2.11.7-7.el9_8.8, libwinpr-devel 2.11.7-13.el9_9.2, freerdp-debuginfo 2.11.7-7.el9_8.8, freerdp-debuginfo 2.11.7-13.el9_9.2, +6 more
    fixed: vendor fix RHSA-2026:76755
  • 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 CRB (v. 8) freerdp-devel 2.11.7-14.el8_10, freerdp-debuginfo 2.11.7-14.el8_10, libwinpr-debuginfo 2.11.7-14.el8_10, freerdp-debugsource 2.11.7-14.el8_10, freerdp-libs-debuginfo 2.11.7-14.el8_10
    fixed: vendor fix RHSA-2026:76747
  • 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 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
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.67% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hw7p-5h2r-83gq referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/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
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Affected products

  • FreeRDP FreeRDP

Classification

Weakness
  • CWE-457 Use of Uninitialized Variable

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.