The vulnerability CVE-2026-9698 affects the Perl DBI module versions prior to 1.648. It arises from a buffer overflow in the error handling code where error messages are written into a 200-byte buffer without enforcing length limits. When error handling options such as RaiseError, PrintError, or HandleError are enabled, an attacker who can influence the error message content may cause a buffer overflow. This overflow can lead to memory corruption, resulting in denial of service or potentially arbitrary code execution. Red Hat's advisory notes that while arbitrary code execution is possible in theory, the attacker cannot control the overflow location, making denial of service the most likely impact. Red Hat has issued patches for affected versions in Red Hat Enterprise Linux 10 and related variants. No mitigation other than patching or restricting access to vulnerable applications is currently recommended.

The vulnerability allows remote attackers to cause a buffer overflow by supplying oversized error messages in applications using vulnerable versions of perl-DBI with certain error handling enabled. This can lead to denial of service through application crashes or memory corruption. Arbitrary code execution is theoretically possible but less likely due to lack of control over overflow location. The CVSS 3.1 base score is 9.8 (critical), reflecting network attack vector, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability.

An official fix is available and has been released by Red Hat for affected products including Red Hat Enterprise Linux 10. Users should apply the security updates provided by Red Hat promptly. Until patched, users are advised to restrict network access to applications using perl-DBI to trusted users only, as no other effective mitigations meeting Red Hat's criteria are currently available.