CVE-2025-2886 — tough
Fix: awslabs/tough@598111fCVE-2025-2886 is a CWE-670 vulnerability in tough. A fix is available for tough — see the affected versions and patch details below.
Terminating targets role delegations are not respected in tough
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-2886.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
toughReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Summary
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.
Impact
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.
Impacted versions: < v0.20.0
Patches
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.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | tough | all versions | 0.20.0cargo update -p tough --precise 0.20.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tough, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tough to 0.20.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-2886 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-2886 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-2886. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-2886 in your dependencies?
O3 Security finds CVE-2025-2886 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.