CVE-2026-41989

Medium

Published: 23 April 2026

Published

23 April 2026

Modified

27 April 2026

KEV Added

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Patch

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CVSS Score 6.7 CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H

EPSS Score 0.0001 3.4th percentile

Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-41989 is a medium-severity Out-of-bounds Write (CWE-787) vulnerability in Gnupg Libgcrypt. Its CVSS base score is 6.7 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 3.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense at a Glance

What attackers do: exploitation maps to Application or System Exploitation (T1499.004).

Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection

addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact

Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.

attack.mitre.org →

Why these techniques?

Heap buffer overflow in gcry_pk_decrypt enables local memory corruption leading to application crashes/DoS via crafted ECDH input (matches Application or System Exploitation sub-technique).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

NVD Description

Libgcrypt before 1.12.2 sometimes allows a heap-based buffer overflow and denial of service via crafted ECDH ciphertext to gcry_pk_decrypt.

Deeper analysisAI

CVE-2026-41989 is a heap-based buffer overflow vulnerability (CWE-787) affecting Libgcrypt versions before 1.12.2. The flaw occurs when the gcry_pk_decrypt function processes crafted ECDH ciphertext, potentially leading to a denial of service. Published on 2026-04-23, it carries a CVSS v3.1 base score of 6.7 (AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H), highlighting medium severity with impacts primarily on integrity and availability.

Exploitation requires local access (AV:L) and high attack complexity (AC:H), but no privileges (PR:N), user interaction (UI:N), or scope change (S:U). An unprivileged local attacker could supply malformed ECDH ciphertext to trigger the buffer overflow in gcry_pk_decrypt, achieving high integrity violation (I:H)—such as memory corruption—and high availability disruption (A:H), like application crashes or denial of service, with no confidentiality impact (C:N).

Advisories recommend upgrading to Libgcrypt 1.12.2, which addresses the issue. Detailed information is available in the GnuPG development ticket at https://dev.gnupg.org/T8211, the GnuPG announce mailing list post at https://lists.gnupg.org/pipermail/gnupg-announce/2026q2/000503.html, and the OSS-Security mailing list discussion at https://www.openwall.com/lists/oss-security/2026/04/21/1.