CVE-2026-26965
What it is
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, in the RLE planar decode path, `planar_decompress_plane_rle()` writes into `pDstData` at `((nYDst+y) * nDstStep) + (4*nXDst) + nChannel` without verifying that `(nYDst+nSrcHeight)` fits in the destination height or that `(nXDst+nSrcWidth)` fits in the destination stride. When `TempFormat != DstFormat`, `pDstData` becomes `planar->pTempData` (sized for the desktop), while `nYDst` is only validated against the **surface** by `is_within_surface()`. A malicious RDP server can exploit this to perform a heap out-of-bounds write with attacker-controlled offset and pixel data on any connecting FreeRDP client. The OOB write reaches up to 132,096 bytes past the temp buffer end, and on the brk heap (desktop ≤ 128×128), an adjacent `NSC_CONTEXT` struct's `decode` function pointer is overwritten with attacker-controlled pixel data — control-flow–relevant corruption (function pointer overwritten) demonstrated under deterministic heap layout (`nsc->decode = 0xFF414141FF414141`). Version 3.23.0 fixes the vulnerability.
At a glance
- Exploitability
- Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.7% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.7% in the next 30 days (EPSS).
- Severity: 8.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.7% · EPSS, next 30 days
- Weakness
- CWE-787 · Out-of-bounds write
- Record status
- Modified
Affected
- Freerdp < 3.23.0
Attack profile CVSS 3.1 · 8.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-26965.md and follow it. Check whether this project is affected by CVE-2026-26965. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/FreeRDP/FreeRDP/commit/a0be5cb87d760bb1c803ad1bb835aa1e73e62abc
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5vgf-mw4f-r33h
References
- https://github.com/FreeRDP/FreeRDP/commit/a0be5cb87d760bb1c803ad1bb835aa1e73e62abc
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5vgf-mw4f-r33h
- https://access.redhat.com/errata/RHSA-2026:19033
- https://access.redhat.com/errata/RHSA-2026:5936
- https://access.redhat.com/errata/RHSA-2026:5939
- https://access.redhat.com/errata/RHSA-2026:6004
- https://access.redhat.com/errata/RHSA-2026:6005
- https://access.redhat.com/errata/RHSA-2026:6384
- https://access.redhat.com/errata/RHSA-2026:6385
- https://access.redhat.com/errata/RHSA-2026:6395
- https://access.redhat.com/errata/RHSA-2026:6396
- https://access.redhat.com/errata/RHSA-2026:6616
- https://access.redhat.com/errata/RHSA-2026:6665
- https://access.redhat.com/errata/RHSA-2026:6712
- https://access.redhat.com/errata/RHSA-2026:6764
- https://access.redhat.com/errata/RHSA-2026:7292
- https://access.redhat.com/security/cve/CVE-2026-26965
- https://bugzilla.redhat.com/show_bug.cgi?id=2442959
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26965.json