CVE-2026-41989
Published: 23 April 2026
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 7.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and SC-13 (Cryptographic Protection).
Deeper analysis
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.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-25192
Vulnerability details
Libgcrypt before 1.12.2 sometimes allows a heap-based buffer overflow and denial of service via crafted ECDH ciphertext to gcry_pk_decrypt.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
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).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires timely remediation of flaws in software components such as Libgcrypt by applying the vendor-supplied update to version 1.12.2 that eliminates the gcry_pk_decrypt buffer overflow.
Requires memory protection mechanisms that can mitigate exploitation of the heap-based buffer overflow triggered by crafted ECDH ciphertext.
Mandates use of approved cryptographic modules whose implementations must be free of the documented Libgcrypt ECDH decryption flaw.