CVE-2026-22856: freerdp Race Condition
CVSS: 8.1v3.1HighAnalyzed
AliasesUBUNTU-CVE-2026-22856DEBIAN-CVE-2026-22856CGA-ccfh-mg58-846fCGA-g4vx-3j4w-x7c7CGA-q3m8-6qm6-682rCGA-v53v-w6qf-vq72
Published 14-01-2026Last modified 26-02-2026
Vulnerability summary
CVE-2026-22856 is a high (CVSS 8.1) Race Condition vulnerability in freerdp. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 24.6% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
8.1/10
010
High · v3.1 (NVD)EPSS score
0.33%
0%100%
Low · +0.01 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github
Advisory lineage
Upstream 0 · Downstream 25 · Related 10MGASA-2026-0086OPENSUSE-SU-2026:10059-1OPENSUSE-SU-2026:10176-1OPENSUSE-SU-2026:20320-1OPENSUSE-SU-2026:20339-1RHSA-2026:10076RHSA-2026:10734RHSA-2026:10735RHSA-2026:10951RHSA-2026:11323RHSA-2026:19033RHSA-2026:6340RHSA-2026:6727RHSA-2026:6743RHSA-2026:6799RHSA-2026:6918RHSA-2026:6958RHSA-2026:9640RHSA-2026:9641SUSE-SU-2026:0345-1SUSE-SU-2026:0417-1SUSE-SU-2026:0421-1SUSE-SU-2026:0449-1SUSE-SU-2026:0559-1USN-8105-1
Timeline
- 14-01-2026PublishedVulnerability first disclosed.
- 26-02-2026Last modifiedVulnerability information updated.
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a race in the serial channel IRP thread tracking allows a heap use‑after‑free when one thread removes an entry from serial->IrpThreads while another reads it. This vulnerability is fixed in 3.20.1.
CVSS metrics
8 scores · 6 sources · 2 versionsMedium 6.8Preferred score · CVE.org (CNA)
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:PSources5 sources · 6.8–7.7
- OSV · UbuntuEcosystem advisory · calculated7.7HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:PDiffers
- OSV · WolfiEcosystem advisory · calculated7.7HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:PDiffers
- OSV · ChainguardEcosystem advisory · calculated7.7HighCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:PDiffers
- NVDNIST6.8MediumCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/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
High 8.1Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.33%
Chance of exploitation in the next 30 days
Percentile
25%
Versus all other CVEs
30-day change
+0.01 pp
From 0.32% on 20-09-2026
20-09-202620-10-2026
EPSS score0.33%
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-w842-c386-fxhvX Refsource CONFIRMREPORTAdvisoryExploitPatchVendor Advisory
