CVE-2026-59886 is a denial of service vulnerability in the pyasn1 library used by Red Hat Hardened Images RPMs. The flaw arises when applications process BER, CER, or DER encoded ASN.1 REAL values with large exponents. Operations such as printing, logging, comparing, or arithmetic on these decoded values cause excessive resource consumption, leading to DoS. The vulnerability is rated as Important by Red Hat and has a CVSS v3 base score of 7.5 (high severity). The advisory provides a security update with fixed RPM packages for mariadb11.8 and related components. Mitigations include avoiding certain operations on decoded REAL values and sanitizing logs. The update is available as version 11.8.8-3.hum1 for affected RPMs on aarch64 and x86_64 architectures.

Exploitation of this vulnerability allows a remote attacker to cause denial of service by forcing the affected application to consume excessive CPU and memory resources during ASN.1 REAL value processing. This results in service unavailability but does not impact confidentiality or integrity. There are no known exploits in the wild at this time.

A security update is available from Red Hat that fixes this vulnerability in the mariadb11.8 RPM packages and related components. Users should apply the update to version 11.8.8-3.hum1 or later. When processing untrusted ASN.1 data with pyasn1, avoid calling prettyPrint(), str(), float(), int(), or performing comparisons or arithmetic on decoded REAL objects. Instead, inspect the raw tuple values and sanitize or filter REAL-typed values before logging. Follow Red Hat's official advisory and update instructions at https://access.redhat.com/errata/RHSA-2026:37094.