CVE-2026-22853: freerdp Out-of-bounds Write
Vulnerability summary
CVE-2026-22853 is a critical (CVSS 9.8) Out-of-bounds Write vulnerability in freerdp. EPSS estimates a 0.78% chance of exploitation in the next 30 days, higher than 55% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 8 · Related 4Timeline
- 14-01-2026PublishedVulnerability first disclosed.
- 19-08-2026Last modifiedVulnerability information updated.
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, RDPEAR’s NDR array reader does not perform bounds checking on the on‑wire element count and can write past the heap buffer allocated from hints, causing a heap buffer overflow in ndr_read_uint8Array. This vulnerability is fixed in 3.20.1.
CVSS metrics
9 scores · 6 sources · 2 versions- 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
- CVE.orgCNA8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HDiffers
- OSV · UbuntuEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HDiffers
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.78%
Chance of exploitation in the next 30 days
Percentile
55%
Versus all other CVEs
30-day change
+0.02 pp
From 0.76% 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 causeAffected systems
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
Ubuntu1 product
- freerdp3< 3.16.0+dfsg-2ubuntu0.3
5 vendors · 8 products
References
14 links- github.com/FreeRDP/FreeRDP/security/advisories/GHSA-47v9-p4gp-w5chX Refsource CONFIRMREPORTAdvisoryExploitVendor Advisory
