GHSA-77hh-43cm-v8j6 — tuf
Fix: theupdateframework/python-tuf@77cb66bGHSA-77hh-43cm-v8j6 is a security vulnerability in tuf. A fix is available for tuf — see the affected versions and patch details below.
tuf's Metadata API: Targets.get_delegated_role() is missing input validation
Real-World Exposure
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Description
The security of both a TUF client and repository implementations depend on the concept of trusted Metadata objects verifying the signatures over other Metadata that it delegates to. This verification process uses Targets.get_delegated_role(delegated_role: str) to find the delegation information.
tuf.api.metadata.Targets.get_delegated_role() should ensure that the given delegated_rolename is actually a name of a role that is delegated by that Targets, but in the case of "succinct delegation" this does not happen.
tuf.ngclient users are not impacted but direct users of tuf.api.metadata could be impacted.
Impact
If an attacker can make a Metadata API user run Targets.get_delegated_role() so that
- the
Targetsuses succinct delegation - the
delegated_roleargument is not actually delegated by theTargets
the result will be incorrect.
This also means that if an attacker can make a Metadata API user run Targets.verify_delegate() or Targets.get_verification_result() so that
- the delegating
Targetsuses a succinct delegation - the
delegated_roleargument is the name of some unrelated Metadata - that other Metadata is correctly signed by the keys defined in the succinct delegation
the result would be a successful verification even though the Targets in question does not actually delegate to delegated_role.
The impact is estimated to be low for following reasons:
- This cannot impact a TUF client that implements the client workflow as specified since the delegated role name is not an input but is collected from the (trusted) delegating Targets itself
- Actual signature verification is not bypassed: The verified metadata must still be correctly signed by the keys specified in the delegating role.
- The described situations are somewhat hypothetical: there does not seem to be any reason for a python-tuf user (whether client or a repository) to use
tuf.api.metadatain this way.
All users of tuf.ngclient are specifically not impacted. Users of tuf.api.metadata could be impacted if they use succinct delegations in a way described above.
Patches
A fix is available in python-tuf 3.1.1 as commit 77cb66bc and in later releases as commit eb4834d9._
Workarounds
tuf.api.metadata users should only call Targets.get_delegated_role(), Targets.verify_delegate() or Targets.get_verification_result() with delegated_role argument that is known to be delegated by the Targets in question.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | tuf | ≥ 2.0.0&&< 3.1.1 | 3.1.1pip install --upgrade 'tuf==3.1.1' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tuf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tuf to 3.1.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-77hh-43cm-v8j6 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 GHSA-77hh-43cm-v8j6 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-77hh-43cm-v8j6. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-77hh-43cm-v8j6 in your dependencies?
O3 Security finds GHSA-77hh-43cm-v8j6 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.