CVE-2026-110264: GitLab Self-Managed Users Urged to Patch Critical Integer Overflow RCE

Self-managed GitLab installations face immediate risk from a critical vulnerability that permits unauthenticated remote code execution. The flaw, tracked as CVE-2026-110264, carries a maximum CVSS score of 10.0. According to Cyber Security News, GitLab published urgent security updates on October 21, 2026, to address the issue. The vulnerability affects both Community Edition and Enterprise Edition products.

Which versions are exposed to this flaw?

The vulnerability impacts a wide range of GitLab releases, extending back to version 7.0, which launched in 2014. According to the NVD record, all versions prior to 18.11.13, 19.0.10, 19.1.9, 19.2.9, 19.3.6, 19.4.3, and 19.5.1 are affected. GitLab extended the fix to four older branches beyond its standard patch releases. Self-managed customers running any of these earlier versions remain exposed until they upgrade.

How does the technical exploit work?

The issue stems from an integer overflow in the regular expression compiler. According to GBHackers, processing a specially crafted regular expression can trigger this overflow. Under certain conditions, this allows an attacker to execute arbitrary code on the server. The CVSS vector indicates network-based access with low complexity, requiring no privileges or user interaction. The potential impact on confidentiality, integrity, and availability is rated as high.

Is this vulnerability currently being exploited?

GitLab’s advisory does not report confirmed attacks or provide a public exploit. According to Cyber Security News, the company describes the risk but has not disclosed full conditions needed to reach the vulnerable code. Administrators should not assume the flaw requires access to a specific project or feature. GitLab.com already runs patched software, and certain Dedicated tenants on internal versions 19.3.5 or later are also protected.

What other issues were patched alongside this one?

This release addresses twelve vulnerabilities in total, including two high-severity weaknesses. According to GBHackers, CVE-2026-15723, rated 8.2, could allow account takeover when OmniAuth SAML and LDAP auto-linking are enabled. CVE-2026-112212, rated 7.5, concerns cache poisoning in OAuth/OIDC discovery endpoints. Security researcher joaxcar reported the critical RCE flaw through the HackerOne bug bounty program.

Detection notes

Teams usually monitor application logs for unexpected crashes or worker failures when investigating potential exploitation of compiler flaws. Check whether native workers are terminating abnormally during routine operations. Look for bursts of render errors that do not match normal traffic patterns. Investigate any sudden spikes in CPU usage or memory consumption that coincide with these errors.

Review network logs for unusual outbound connections from the application layer. Isolate affected systems immediately if suspicious behavior is confirmed. Do not rely solely on automated alerts; manual verification of process integrity is essential. Ensure that logging mechanisms are capturing sufficient detail to reconstruct the sequence of events.

Background: Integer overflow vulnerabilities

Integer overflow vulnerabilities occur when calculations exceed maximum storage limits, causing values to wrap around. Small businesses face exposure through outdated software and misconfigured systems. Protect assets by enforcing strict input validation, applying security patches promptly, and verifying that IT providers monitor firmware vulnerabilities and security misconfigurations regularly.

Read the full guide: Integer Overflow Vulnerabilities: Risks and Protection for Small Businesses

What to do and how to stay safe: GitLab

• Verify your current GitLab version against the list of fixed releases provided by the vendor.
• Apply the latest security update to all self-managed Community and Enterprise Edition installations.
• Monitor application logs for native worker crashes or render errors that may indicate exploitation attempts.
• Review access logs for unusual activity from unauthenticated users targeting regular expression inputs.

Step-by-step guide: Patch Management Checklist: Secure Systems Without Breaking Them

General security guidance from the Firewall Scoop newsroom. It is not confirmed advice from the organisations named in this story.

Frequently asked questions

Does this vulnerability affect GitLab.com hosted instances?

No, GitLab.com already runs patched software and is not affected by this vulnerability.

How was this vulnerability discovered and reported?

Security researcher joaxcar reported the issue through GitLab’s HackerOne bug bounty program.

Are there any confirmed attacks in the wild using this flaw?

No, GitLab has not reported confirmed attacks or provided a public exploit for this vulnerability.