GHSA-96c6-m98x-hxjx is a medium-severity (CVSS 6.5) vulnerability in zendframework/zend-session. A fix is available for zendframework/zend-session — see the affected versions and patch details below.
Zend-Session session validation vulnerability
Real-World Exposure
zendframework/zend-session🐘zendframework/zend-sessionReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Zend\Session session validators do not work as expected if set prior to the start of a session.
For instance, the following test case fails (where $this->manager is an instance of Zend\Session\SessionManager):
$this
->manager
->getValidatorChain()
->attach('session.validate', array(new RemoteAddr(), 'isValid'));
$this->manager->start();
$this->assertSame(
array(
'Zend\Session\Validator\RemoteAddr' =3D> '',
),
$_SESSION['__ZF']['_VALID']
);
The implication is that subsequent calls to Zend\Session\SessionManager#start() (in later requests, assuming a session was created) will not have any validator metadata attached, which causes any validator metadata to be re-built from scratch, thus marking the session as valid.
An attacker is thus able to simply ignore session validators such as RemoteAddr or HttpUserAgent, since the "signature" that these validators check against is not being stored in the session.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | zendframework/zend-session | ≥ 2.0.0&&< 2.2.9 | 2.2.9composer require zendframework/zend-session:^2.2.9 |
| 🐘Packagist | zendframework/zend-session | ≥ 2.3.0&&< 2.3.4 | 2.3.4composer require zendframework/zend-session:^2.3.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for zendframework/zend-session, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update zendframework/zend-session to 2.2.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-96c6-m98x-hxjx 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-96c6-m98x-hxjx can be triaged on real exposure rather than presence alone.
Tailored to GHSA-96c6-m98x-hxjx. 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-96c6-m98x-hxjx in your dependencies?
O3 Security finds GHSA-96c6-m98x-hxjx across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.