How severe is GHSA-8x3w-qj7j-gqhf?

No CVSS score has been assigned to GHSA-8x3w-qj7j-gqhf yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-8x3w-qj7j-gqhf?

GHSA-8x3w-qj7j-gqhf affects the following packages: openmls (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-8x3w-qj7j-gqhf?

Update openmls to 0.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8x3w-qj7j-gqhf is resolved across your whole dependency graph.

How do I detect GHSA-8x3w-qj7j-gqhf in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openmls. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-8x3w-qj7j-gqhf if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-8x3w-qj7j-gqhf?

O3 pinpoints whether GHSA-8x3w-qj7j-gqhf is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-8x3w-qj7j-gqhf actively exploited in the wild?

No public exploit code has been indexed for GHSA-8x3w-qj7j-gqhf yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-8x3w-qj7j-gqhf published, and has it been updated?

GHSA-8x3w-qj7j-gqhf was published on February 4, 2026 and was last updated on February 4, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

GHSA-8x3w-qj7j-gqhf: openmls has improper tag validation

Blast Radius

1 pkg affected

🦀openmls

Real-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

Membership and confirmation tags may not be checked correctly due to a missing length check. Any tag that is shorter than the expected tag, but matches up to its length, as well as any empty tag is considered valid.

Impact

The vulnerability affects a secondary authentication guarantee that MLS provides in certain scenarios. The primary authentication guarantee for all messages comes from the signature on MLS messages. This guarantee is not affected by the vulnerability.
The secondary authentication attests to the group membership of the message author. For MLS private messages, it is implied in the AEAD. For MLS public messages, it is expressed as the ‘membership tag’, a MAC whose key is derived from the private group state only known to group members.

In addition, for public Commit messages, the ‘confirmation tag’ works in a similar manner. Its purpose is to help members who processed the Commit message to ascertain that they now have the same view on the group as the creator of the Commit message for both the private and public group state.

The vulnerability lets an attacker create MLS messages with a truncated tag that are considered valid nonetheless.

The vulnerability does not affect the primary authentication guarantees of MLS, but breaks post-compromise security (PCS) of the MLS authentication guarantees. As a consequence, an adversary that has compromised a member’s signature key can create valid-looking proposals even after the affected member has successfully updated its key material. However, this is only possible in applications where the following conditions are met:

The application uses public MLS messages (i.e. it has not restricted the wire format type to private MLS messages only), and
the application supports proposals by reference (aka standalone proposals).

Note that, in deployments that allow external Commits, an attacker in possession of a member’s signature key can insert itself into the group without having to forge a membership tag.

Patches

There are two ways to mitigate the issue:

Upgrade to openmls v0.7.2: This minor release includes a fix for the issue and bumps the libcrux dependencies. This release does not contain any breaking changes from v0.7.1.
Upgrade to openmls v0.8.0: This release contains the fix, as well as other improvements. The list of changes is in CHANGELOG.md. Some of the changes are breaking API changes.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`openmls`	all versions	0.7.2

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openmls. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update openmls to 0.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8x3w-qj7j-gqhf 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 pinpoints whether GHSA-8x3w-qj7j-gqhf is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-8x3w-qj7j-gqhf. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Membership and confirmation tags may not be checked correctly due to a missing length check. Any tag that is shorter than the expected tag, but matches up to its length, as well as any empty tag is considered valid. ### Impact The vulnerability affects a secondary authentication guarantee that MLS provides in certain scenarios. The primary authentication guarantee for all messages comes from the signature on MLS messages. This guarantee is *not* affected by the vulnerability. The secondary authentication attests to the group membership of the message author. For MLS private messages, it is

O3 Security · Impact-Aware SCA

Is GHSA-8x3w-qj7j-gqhf in your dependencies?

O3 detects GHSA-8x3w-qj7j-gqhf across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

GHSA-8x3w-qj7j-gqhf