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Fencer Vulns
medium 6.5

CVE-2026-91963 json

FreeRDP 2.0.0 through 3.30.0 Uninitialized Heap Memory Disclosure via urbdrc

published 2026-09-15 54 d ago modified 2026-09-23 46 d ago also EUVD-2026-78639

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

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 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, libwinpr 2.11.7-7.el9_8.8, freerdp-libs 2.11.7-7.el9_8.8
    fixed: vendor fix RHSA-2026:76755
  • Red Hat Enterprise Linux AppStream (v. 10) freerdp 3.10.3-12.el10_2.14, 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
  • 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
show 6 more
  • 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, libwinpr-devel 2.11.7-7.el9_8.8, freerdp-debuginfo 2.11.7-7.el9_8.8, libwinpr-debuginfo 2.11.7-7.el9_8.8, freerdp-debugsource 2.11.7-7.el9_8.8, freerdp-libs-debuginfo 2.11.7-7.el9_8.8
    fixed: vendor fix RHSA-2026:76755
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) 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
54 d ago

Exploit prediction

0.66% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-08).

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 Vulns 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.