CVE-2026-96399

Summary

A Gitea repository's external issue tracker configuration with alternating capture groups in regular expressions can cause runtime panics when rendering issue references, leading to complete service termination. An attacker with repository edit access can crash the entire Gitea instance by crafting malicious regex patterns.

Exploitability

Moderately difficult to exploit as it requires an attacker to have repository edit permissions and to configure a malicious external issue tracker regex pattern that triggers invalid slice indexing during content rendering.

Blast radius

High impact in production environments where Gitea serves multiple users, as the crash affects all users until the service is manually restarted, potentially causing extended downtime.

Detection

Monitor for process crashes or restarts of the Gitea service, and check application logs for panic messages related to slice indexing errors during issue reference rendering.

Prioritized remediation

Upgrade to Gitea version 2.590 or later to receive the fix for the invalid slice indexing issue in external issue tracker regex processing.

Analysis generated locally by garnet-coder (no data left the box). AI-assisted — verify against primary sources before acting.