CVE-2026-91948
FreeRDP before 3.31.0 Out-of-bounds Write via SHOW_PROTOCOL
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
FreeRDP before 3.31.0 Out-of-bounds Write via SHOW_PROTOCOL
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.
- Record
CVE-2026-91948- CVSS 4.0
- 7.7 High
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-191
- Updated
- 2026-11-02
EUVDEUVD-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.
- Record
EUVD-2026-78805- CVSS 4.0
- 7.7 High
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-vg28-cmpq-3hp8
FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in server-side static...
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.
- Record
GHSA-vg28-cmpq-3hp8- CVSS 4.0
- 7.7 High
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-191
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-91948- CVSS 4.0
- 7.7 High
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-191
- Updated
- 2026-11-02
OSV
FreeRDP before 3.31.0 Out-of-bounds Write via SHOW_PROTOCOL
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.
- Record
CVE-2026-91948- CVSS 4.0
- 7.7 High
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 - Weakness
- CWE-191
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-91948
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.
- Record
DEBIAN-CVE-2026-91948- CVSS 4.0
- 7.7 High
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 - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-91948
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.
- Record
UBUNTU-CVE-2026-91948- CVSS 4.0
- 7.7 High
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
freerdp3Debian:14 | before 3.31.0+dfsg-1, plus listed versions 3.15.0+dfsg-2.13.16.0+dfsg-13.16.0+dfsg-23.17.0+dfsg-13.17.1+dfsg-1 Show 35 moreShow less3.17.1+dfsg-23.17.2+dfsg-13.17.2+dfsg-23.17.2+dfsg-33.18.0+dfsg-13.19.0+dfsg-13.19.1+dfsg-13.20.0+dfsg-13.20.2+dfsg-13.21.0+dfsg-13.22.0+dfsg-13.22.0+dfsg-1~bpo13+03.22.0+dfsg-1~bpo13+13.22.0+dfsg-33.23.0+dfsg-13.23.0+dfsg-1~bpo13+13.24.0+dfsg-13.24.0+dfsg-23.24.1+dfsg-13.24.2+dfsg-13.24.2+dfsg-1~bpo13+13.25.0+dfsg-13.25.0+dfsg-23.25.0+dfsg-33.25.0+dfsg-43.25.0+dfsg-53.26.0+dfsg-13.26.0+dfsg-1~bpo13+13.27.0+dfsg-13.27.1+dfsg-13.28.0+dfsg-13.28.0+dfsg-23.29.0+dfsg-13.30.0+dfsg-13.30.0+dfsg-1~bpo13+1 | 3.31.0+dfsg-1 |
freerdpUbuntu:16.04:LTS | All versions, plus listed versions 1.1.0~git20140921.1.440916e+dfsg1-5ubuntu11.1.0~git20140921.1.440916e+dfsg1-5ubuntu1.21.1.0~git20140921.1.440916e+dfsg1-5ubuntu1.31.1.0~git20140921.1.440916e+dfsg1-5ubuntu1.4 | None known |
freerdp2Ubuntu:Pro:18.04:LTS | All versions, plus listed versions 2.0.0~git20170725.1.1648deb+dfsg1-12.0.0~git20170725.1.1648deb+dfsg1-52.0.0~git20170725.1.1648deb+dfsg1-5ubuntu12.0.0~git20170725.1.1648deb+dfsg1-5ubuntu22.0.0~git20170725.1.1648deb+dfsg1-6 Show 14 moreShow less2.0.0~git20170725.1.1648deb+dfsg1-6build12.0.0~git20170725.1.1648deb+dfsg1-72.0.0~git20170725.1.1648deb+dfsg1-7ubuntu0.12.1.1+dfsg1-0ubuntu0.18.04.12.2.0+dfsg1-0ubuntu0.18.04.12.2.0+dfsg1-0ubuntu0.18.04.22.2.0+dfsg1-0ubuntu0.18.04.32.2.0+dfsg1-0ubuntu0.18.04.42.2.0+dfsg1-0ubuntu0.18.04.4+esm12.2.0+dfsg1-0ubuntu0.18.04.4+esm22.2.0+dfsg1-0ubuntu0.18.04.4+esm32.2.0+dfsg1-0ubuntu0.18.04.4+esm42.2.0+dfsg1-0ubuntu0.18.04.4+esm52.2.0+dfsg1-0ubuntu0.18.04.4+esm6 | None known |
freerdpUbuntu:18.04:LTS | All versions, plus listed versions 1.1.0~git20140921.1.440916e+dfsg1-15ubuntu11.1.0~git20140921.1.440916e+dfsg1-15ubuntu1.18.04.11.1.0~git20140921.1.440916e+dfsg1-15ubuntu1.18.04.2 | None known |
freerdp2Ubuntu:Pro:20.04:LTS | All versions, plus listed versions 2.0.0~git20190204.1.2693389a+dfsg1-12.0.0~git20190204.1.2693389a+dfsg1-22.0.0~git20190204.1.2693389a+dfsg1-2build12.0.0~git20190204.1.2693389a+dfsg1-2build22.1.1+dfsg1-0ubuntu0.20.04.1 Show 12 moreShow less2.2.0+dfsg1-0ubuntu0.20.04.12.2.0+dfsg1-0ubuntu0.20.04.22.2.0+dfsg1-0ubuntu0.20.04.32.2.0+dfsg1-0ubuntu0.20.04.42.2.0+dfsg1-0ubuntu0.20.04.52.2.0+dfsg1-0ubuntu0.20.04.62.6.1+dfsg1-0ubuntu0.20.04.12.6.1+dfsg1-0ubuntu0.20.04.22.6.1+dfsg1-0ubuntu0.20.04.2+esm12.6.1+dfsg1-0ubuntu0.20.04.2+esm22.6.1+dfsg1-0ubuntu0.20.04.2+esm32.6.1+dfsg1-0ubuntu0.20.04.2+esm4 | None known |
freerdp2Ubuntu:22.04:LTS | All versions, plus listed versions 2.3.0+dfsg1-2build12.3.0+dfsg1-2ubuntu12.3.0+dfsg1-2ubuntu22.4.1+dfsg1-12.4.1+dfsg1-1ubuntu1 Show 18 moreShow less2.4.1+dfsg1-1ubuntu22.5.0+dfsg1-12.6.0+dfsg1-12.6.1+dfsg1-12.6.1+dfsg1-32.6.1+dfsg1-3ubuntu12.6.1+dfsg1-3ubuntu22.6.1+dfsg1-3ubuntu2.12.6.1+dfsg1-3ubuntu2.22.6.1+dfsg1-3ubuntu2.32.6.1+dfsg1-3ubuntu2.42.6.1+dfsg1-3ubuntu2.52.6.1+dfsg1-3ubuntu2.62.6.1+dfsg1-3ubuntu2.72.6.1+dfsg1-3ubuntu2.82.6.1+dfsg1-3ubuntu2.92.6.1+dfsg1-3ubuntu2.102.6.1+dfsg1-3ubuntu2.11 | None known |
freerdp3Ubuntu:24.04:LTS | before 3.31.0+dfsg-0ubuntu0.24.04.1, plus listed versions 3.4.0+dfsg1-0ubuntu23.4.0+dfsg1-0ubuntu33.4.0+dfsg1-0ubuntu43.5.0+dfsg1-0ubuntu13.5.1+dfsg1-0ubuntu1 Show 7 moreShow less3.5.1+dfsg1-0ubuntu1.13.5.1+dfsg1-0ubuntu1.23.5.1+dfsg1-0ubuntu1.43.5.1+dfsg1-0ubuntu1.53.5.1+dfsg1-0ubuntu1.63.30.0+dfsg-0ubuntu0.24.04.13.30.0+dfsg-0ubuntu0.24.04.2 | 3.31.0+dfsg-0ubuntu0.24.04.1 |
freerdp2Ubuntu:Pro:24.04:LTS | All versions, plus listed versions 2.10.0+dfsg1-1.1ubuntu12.11.2+dfsg1-12.11.2+dfsg1-1build12.11.2+dfsg1-1build32.11.5+dfsg1-1build1 Show 7 moreShow less2.11.5+dfsg1-1build22.11.5+dfsg1-1ubuntu0.1~esm12.11.5+dfsg1-1ubuntu0.1~esm22.11.5+dfsg1-1ubuntu0.1~esm32.11.5+dfsg1-1ubuntu0.1~esm42.11.5+dfsg1-1ubuntu0.1~esm52.11.5+dfsg1-1ubuntu0.1~esm6 | None known |
freerdp3Ubuntu:26.04:LTS | before 3.31.0+dfsg-0ubuntu0.26.04.1, plus listed versions 3.16.0+dfsg-23.18.0+dfsg-1ubuntu13.19.0+dfsg-13.19.1+dfsg-13.20.0+dfsg-1 Show 8 moreShow less3.20.2+dfsg-13.21.0+dfsg-13.22.0+dfsg-13.24.1+dfsg-1ubuntu13.24.2+dfsg-1ubuntu13.24.2+dfsg-1ubuntu1.13.30.0+dfsg-0ubuntu0.26.04.13.30.0+dfsg-0ubuntu0.26.04.2 | 3.31.0+dfsg-0ubuntu0.26.04.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-91948 is a high vulnerability (CVSS 7.7) in Freerdp, published September 15, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.59%, the 48th percentile. Fixed in freerdp3 3.31.0+dfsg-1.
References
github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9jcm-x588-gh26
vulncheck.com/advisories/freerdp-before-3.31.0-out-of-bounds-write-via-show-protocol
nvd.nist.gov/vuln/detail/CVE-2026-91948