CVE-2026-72887
Fix: vurtdev/Net-OAuth@fd505daCVE-2026-72887 is a CWE-757 vulnerability. O3 Security confirms whether CVE-2026-72887 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Net::OAuth::Client versions before 0.32 for Perl allow the service provider to silently downgrade OAuth 1.0a to OAuth 1.0 in get_request_token. Passing a callback to the constructor…
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2026-72887.
Description
Net::OAuth::Client versions before 0.32 for Perl allow the service provider to silently downgrade OAuth 1.0a to OAuth 1.0 in get_request_token.
Passing a callback to the constructor selects OAuth 1.0a. get_request_token then revokes that choice when the request token response omits oauth_callback_confirmed, with no exception, no warning and no option to require 1.0a. The access token request is built from the OAuth 1.0 message class, which has no verifier parameter, so oauth_verifier is dropped from the request even when get_access_token was passed one.
oauth_verifier is the binding that OAuth 1.0a added between the authorization step and the token exchange. An application that asked for 1.0a and gets 1.0 is open to OAuth 1.0 session fixation, where an attacker obtains a request token, has the victim authorize it, and then completes the exchange themselves, linking the victim's provider account to a session the attacker controls. No attacker action sets up the downgrade: a provider that does not confirm the callback is enough.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. 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.
Remediation status
No patched version of the affected component has shipped for CVE-2026-72887 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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 CVE-2026-72887 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 CVE-2026-72887. 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-2026-72887 in your dependencies?
O3 detects CVE-2026-72887 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.