Summary
Credit
Thanks to the 3 separate reports from @celinke97, @N0zoM1z0 and @AyushParkara. Thanks for finding and reporting this issue privately to the go-git project. :bow:
Impact
go-git may leak HTTP authentication credentials when following redirects during smart-HTTP clone and fetch operations.
If a remote repository responds to the initial /info/refs request with a redirect to a different host, go-git updates the session endpoint to the redirected location and reuses the original authentication for subsequent requests. This can result in the credentials (e.g. Authorization headers) being sent to an unintended host.
An attacker controlling or influencing the redirect target can capture these credentials and potentially reuse them to access the victim’s repositories or other resources, depending on the scope of the credential.
Clients using go-git exclusively with trusted remotes (for example, GitHub or GitLab), and over a secure HTTPS connection, are not affected by this issue. The risk arises when interacting with untrusted or misconfigured Git servers, or when using unsecured HTTP connections, which is not recommended. Such configurations also expose clients to a broader class of security risks beyond this issue, including credential interception and tampering of repository data.
CVE-2026-41506 has a CVSS score of 4.7 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.18.0, 6.0.0-alpha.2); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
Users should upgrade to v5.18.0, or v6.0.0-alpha.2, in order to mitigate this vulnerability. Versions prior to v5 are likely to be affected, users are recommended to upgrade to a supported go-git version.
The patched versions add support for configuring followRedirects. In line with upstream behaviour, the default is now initial, while users can opt into FollowRedirects or NoFollowRedirects programmatically.
Frequently Asked Questions
- What is CVE-2026-41506? CVE-2026-41506 is a medium-severity security vulnerability in github.com/go-git/go-git/v5 (go), affecting versions <= 5.17.2. It is fixed in 5.18.0, 6.0.0-alpha.2.
- How severe is CVE-2026-41506? CVE-2026-41506 has a CVSS score of 4.7 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2026-41506?
github.com/go-git/go-git/v5(go) (versions <= 5.17.2)github.com/go-git/go-git/v6(go) (versions <= 6.0.0-alpha.1)
- Is there a fix for CVE-2026-41506? Yes. CVE-2026-41506 is fixed in 5.18.0, 6.0.0-alpha.2. Upgrade to this version or later.
- Is CVE-2026-41506 exploitable, and should I be worried? Whether CVE-2026-41506 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-41506 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-41506?
- Upgrade
github.com/go-git/go-git/v5to 5.18.0 or later - Upgrade
github.com/go-git/go-git/v6to 6.0.0-alpha.2 or later
- Upgrade