CVE-2025-2886

Delegations are a mechanism defined by the TUF specification that allow multiple different identities to provide and sign content within a single repository. Terminating delegations and delegation priority give a TUF repository unambiguous control over how overlapping delegations are resolved. tough erroneously will not terminate a search as required, and will accept information from a lower-priority delegation that should have been ignored.

Impacted versions: < v0.20.0

Workarounds

There is no recommended work around. Customers are advised to upgrade to version 0.20.0 or the latest version.

References

If you have any questions or comments about this advisory we ask that you contact AWS/Amazon Security via our vulnerability reporting page [1] or directly via email to [email protected]. Please do not create a public GitHub issue.

[1] Vulnerability reporting page: https://aws.amazon.com/security/vulnerability-reporting

Acknowledgement

These issues were identified by the TUF-Conformance project. We would like to thank Google for collaborating on this issue through the coordinated vulnerability disclosure process.

When interacting with TUF repositories that use delegations, the tough client could fetch targets owned by the incorrect role. An actor which had delegated ownership of a subset of a TUF repository could provide arbitrary contents to tough clients for targets owned by the delegating identity.

CVE-2025-2886 has a CVSS score of 4.2 (Medium). The vector is network-reachable, high 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 (0.20.0); upgrading removes the vulnerable code path.

Kodem intelligence

A fix for this issue is available in tough version 0.20.0 and later. Customers are advised to upgrade to version 0.20.0 or later and ensure any forked or derivative code is patched to incorporate the new fixes.

1. What is CVE-2025-2886? CVE-2025-2886 is a medium-severity security vulnerability in tough (rust), affecting versions < 0.20.0. It is fixed in 0.20.0.
2. How severe is CVE-2025-2886? CVE-2025-2886 has a CVSS score of 4.2 (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.
3. Which versions of tough are affected by CVE-2025-2886? tough (rust) versions < 0.20.0 is affected.
4. Is there a fix for CVE-2025-2886? Yes. CVE-2025-2886 is fixed in 0.20.0. Upgrade to this version or later.
5. Is CVE-2025-2886 exploitable, and should I be worried? Whether CVE-2025-2886 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
6. What actually determines whether CVE-2025-2886 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.
7. How do I fix CVE-2025-2886? Upgrade tough to 0.20.0 or later.