CVSS 4.0
9.1 criticalCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NCVE-2026-121392
Critical (9.1) in freerdp freerdp. EPSS 0.2% estimated probability of exploitation activity in the next 30 days.
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FreeRDP before 3.32.2 contains an improper certificate validation vulnerability in tls_verify_certificate() that accepts Common Name fallback despite non-matching SAN entries and matches IP literals against DNS strings. Man-in-the-middle attackers holding a certificate from a client-trusted CA can bypass server identity checks to intercept RDP sessions, including keystrokes, clipboard, and screen content.
Severity
CVSS 3.1
7.4 highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N- EPSS
- 0.2% estimated probability of exploitation activity in the next 30 days; 6th percentile. Scored 2026-11-04. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: total, assessed 2026-11-03. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-295 Improper Certificate Validation
- OWASP Top 10
- A07:2025 Authentication Failures
- Published
- Modified
- Record from
- the NVD, synced
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Explain CVE-2026-121392 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-121392?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-121392?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-121392 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| FreeRDP | before 3.32.2 |
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12 | freerdp2 | no fix listed | DEBIAN-CVE-2026-121392 |
| Debian | 13 | freerdp3 | no fix listed | DEBIAN-CVE-2026-121392 |
| Debian | 14 | freerdp3 | 3.32.2+dfsg-1 | DEBIAN-CVE-2026-121392 |
From the distributions' data via OSV.dev: the Debian Security Tracker. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian.
Attack patterns (CAPEC)
- CAPEC-459 Creating a Rogue Certification Authority Certificate Likelihood: Medium · Severity: Very High
- CAPEC-475 Signature Spoofing by Improper Validation Likelihood: Low · Severity: High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.