Is CVE-2026-23531 in the CISA KEV catalog?

No. CVE-2026-23531 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-23531?

CVE-2026-23531 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2026-23531?

CVE-2026-23531 has an EPSS score of 0.58% (43th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-23531

CRITICAL

9.8

CVSS v3

NVD

Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, in ClearCodec, when `glyphData` is present, `clear_decompress` calls `freerdp_image_copy_no_overlap` without validating the destination rectangle, allowing an out-of-bounds read/write via crafted RDPGFX surface updates. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

CWE-122Heap-based Buffer Overflow

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

0.58%probability of exploitation in 30 days

43rdpercentile

Moderate risk: more likely to be exploited than 43% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-01-28.