CVE-2026-7771 is a vulnerability in IBM Db2 affecting versions 11.5.0 through 11.5.9 and 12.1.0 through 12.1.4. The issue arises when the database engine compiles specially crafted SQL statements containing subqueries, leading to a loop with an unreachable exit condition (CWE-835). This results in a denial of service condition by causing the process to hang indefinitely. The vulnerability does not impact confidentiality or integrity but affects availability. No known exploits are reported in the wild, and no official remediation or patch has been announced as of the publication date.

The vulnerability causes a denial of service by triggering an infinite loop during statement compilation, which can cause the Db2 service to become unresponsive. There is no impact on data confidentiality or integrity. The medium severity rating reflects the availability impact without privilege requirements or user interaction beyond statement submission.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, avoid executing specially crafted statements with complex subqueries that could trigger the issue. Monitor IBM's security advisories for updates on patches or workarounds.