Summary
tough cyclic delegation graphs are not detected
In a TUF repository, the targets role’s signature indicates which target files are trusted by clients. The role can delegate full or partial trust to other roles, meaning that that role is trusted to sign target file metadata. Delegated roles can further delegate trust to other delegated roles. When searching for metadata about a given target, tough failed to detect cyclical role delegations.
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.
Impact
When interacting with TUF repositories which contain cyclical role delegations, tough will fail to detect the cycles and will exhaust its stack while recursively searching the delegation graph. The exhausted call stack will cause the process to abort.
GHSA-J8X2-777P-23FC has a CVSS score of 2.7 (Low). The vector is network-reachable, high privileges required, and no user interaction. 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.
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.
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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.
Frequently Asked Questions
- What is GHSA-J8X2-777P-23FC? GHSA-J8X2-777P-23FC is a low-severity security vulnerability in tough (rust), affecting versions < 0.20.0. It is fixed in 0.20.0.
- How severe is GHSA-J8X2-777P-23FC? GHSA-J8X2-777P-23FC has a CVSS score of 2.7 (Low). 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 versions of tough are affected by GHSA-J8X2-777P-23FC? tough (rust) versions < 0.20.0 is affected.
- Is there a fix for GHSA-J8X2-777P-23FC? Yes. GHSA-J8X2-777P-23FC is fixed in 0.20.0. Upgrade to this version or later.
- Is GHSA-J8X2-777P-23FC exploitable, and should I be worried? Whether GHSA-J8X2-777P-23FC 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 GHSA-J8X2-777P-23FC 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 GHSA-J8X2-777P-23FC? Upgrade
toughto 0.20.0 or later.