What's the vulnerability?
Net::OAuth versions before 0.32 for Perl allow memory exhaustion via unbounded caching of failed module loads in smart_require. smart_require stores results in a process-global hash with no bound and no eviction, and keeps an entry for every class name it is asked about, including names that failed to load, because the return value of the failed eval is stored before the error is checked. The key comes off the wire on the server side: _signature_method_class builds the class name from the signature_method parameter of the incoming message, and verify resolves it before any signature is checked. A remote client chooses both how many entries are created and how long each key is. In a persistent server the hash grows for the life of the worker process until it exhausts memory. Header size limits bound the key length on the Authorization header path, but not on a POST body.
Business impact & how R4IM helps
This advisory is on our active-exploitation watchlist. Attackers are using it for initial access, privilege escalation or lateral movement in real-world intrusions. R4IM's offensive security and SOC teams already have detections, exploit replicas and remediation playbooks for this issue.
Targeted vulnerability assessment to confirm which of your assets are actually exploitable — not just theoretically affected.
Our pentesters chain this CVE into realistic attack paths so you see business impact, not just a scan finding.
If the affected product is internet-facing, our AppSec team will harden it against this and related OWASP-class issues.
Continuous monitoring with custom detections for this CVE deployed across your endpoints, identity and cloud.
Recommended remediation
- Inventory all assets running the affected vendor and product, including shadow IT and third-party hosted instances.
- Apply the vendor patch or mitigation referenced in the advisories below. Where no patch exists, isolate the asset or restrict network exposure.
- Hunt for indicators of prior compromise — exploitation of this class of bug often predates public disclosure.
- Deploy detections for the exploit primitives (network signature, EDR rule, WAF rule) and re-test after remediation.
Need help executing these steps? Our team typically completes validation and remediation within a single patch cycle. Request remediation support →
Vendor & research references
- https://github.com/vurtdev/Net-OAuth/commit/ee713fc96263c70b3b9a5280612618b474576f8f.patch · 9b29abf9-4ab0-4765-b253-1875cd9b441e
- https://github.com/vurtdev/Net-OAuth/security/advisories/GHSA-m2cv-cq5x-47ph · 9b29abf9-4ab0-4765-b253-1875cd9b441e
- https://metacpan.org/release/RRWO/Net-OAuth-0.32/changes · 9b29abf9-4ab0-4765-b253-1875cd9b441e
- http://www.openwall.com/lists/oss-security/2026/08/16/4 · af854a3a-2127-422b-91ae-364da2661108
