Out-of-Bounds Read in FreeRDP (CVE-2026-22855)
Summary
Vulnerability in FreeRDP (CVE-2026-22855). Confidential information can be exposed externally. Mitigation: upgrade to 3.20.1 or later.
Original description
The description as published by the source.
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a heap out-of-bounds read occurs in the smartcard SetAttrib path when cbAttrLen does not match the actual NDR buffer length. This vulnerability is fixed in 3.20.1.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-22855 has been found in FreeRDP.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: upgrade FreeRDP to 3.20.1 or later.
If unsure, ask your IT team or search "FreeRDP CVE-2026-22855" on the vendor's site.
CVE-2026-22855 (FreeRDP) — CWE-125 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 3.20.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Out-of-bounds read (CWE-125) exists in FreeRDP.
Check the vendor advisory for the affected versions of FreeRDP.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to 3.20.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'FreeRDP' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'FreeRDP' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
FreeRDPを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade FreeRDP to 3.20.1ステージング環境で 3.20.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-22855 freerdp2
- Ubuntu UBUNTU-CVE-2026-22855 freerdp
References
- advisory github.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory access.redhat.com
- advisory github.com
- advisory nvd.nist.gov
- report bugzilla.redhat.com
- web github.com
- web security.access.redhat.com