Executive brief
A security flaw has been identified in GnuTLS, a widely used library that enables secure communication for many applications and operating systems. The vulnerability occurs when the software processes specifically formatted digital certificate files (PKCS#12), potentially allowing an attacker to crash the application or service using the library. This could lead to a denial of service, disrupting business operations that rely on secure network connections.
Technical details
An off-by-one error (CWE-193) exists in GnuTLS within the PKCS#12 bag element bounds checking logic. When an application attempts to append an element to a PKCS#12 bag that already contains 32 elements, the library fails to properly validate the array boundaries, resulting in a write past the internal array. This memory corruption can be triggered by a remote attacker providing a malformed PKCS#12 structure. The primary impact is a denial of service (DoS) via application crash, though other unspecified impacts resulting from memory corruption cannot be entirely ruled out. Red Hat has released security advisories (RHSA-2026:20611, RHSA-2026:20612, RHSA-2026:20613) to address this in Enterprise Linux versions 8, 9, and 10.
Affected products
- GnuTLS gnutls
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat Enterprise Linux 10
Timeline
- 2026-05-07: disclosed: Reported by Zou Dikai via Red Hat Bugzilla
- 2026-05-26: patched: Red Hat released security advisories for RHEL 8, 9, and 10
- 2026-05-26: advisory: NVD published CVE-2026-42015