CVE-2026-22851: freerdp Race Condition
Vulnerability summary
CVE-2026-22851 is a medium (CVSS 6.9) Race Condition vulnerability in freerdp. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 20.3% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 5 · Related 4Timeline
- 14-01-2026PublishedVulnerability first disclosed.
- 14-01-2026Last modifiedVulnerability information updated.
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a race condition between the RDPGFX dynamic virtual channel thread and the SDL render thread leads to a heap use-after-free. Specifically, an escaped pointer to sdl->primary (SDL_Surface) is accessed after it has been freed during RDPGFX ResetGraphics handling. This vulnerability is fixed in 3.20.1.
CVSS metrics
8 scores · 6 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.2HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:PDiffers
- OSV · WolfiEcosystem advisory · calculated8.2HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:PDiffers
- OSV · ChainguardEcosystem advisory · calculated8.2HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:PDiffers
- NVDNIST6.9MediumCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/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
- OSV · DebianEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.29%
Chance of exploitation in the next 30 days
Percentile
20%
Versus all other CVEs
30-day change
+0.01 pp
From 0.28% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundFreerdp
Maturity: poc
Weaknesses
CWE · root cause- CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Affected systems
Ubuntu3 products
- freerdpAll versions (No fix recorded)
- freerdp2All versions (No fix recorded)
- freerdp3< 3.5.1+dfsg1-0ubuntu1.4 | < 3.16.0+dfsg-2ubuntu0.3 | < 3.20.2+dfsg-1
Chainguard2 products
- freerdp-devAll versions (No fix recorded)
- freerdp-libsAll versions (No fix recorded)
Debian2 products
- freerdp2All versions (No fix recorded)
- freerdp3< 3.15.0+dfsg-2.1+deb13u1 | < 3.20.2+dfsg-1
Wolfi2 products
- freerdp-devAll versions (No fix recorded)
- freerdp-libsAll versions (No fix recorded)
Freerdp1 product
- freerdp< 3.20.1
5 vendors · 10 products
References
8 links- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-8g87-6pvc-wh99X Refsource CONFIRMREPORTAdvisoryExploitVendor Advisory
