GHSA-w9hf-35q4-vcjw
nosurf vulnerable to CSRF due to non-functional same-origin request checks
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
github.com/justinas/nosurfReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
This vulnerability allows an attacker who controls content on the target site, or on a subdomain of the target site (either via XSS, or otherwise) to bypass Cross-Site Request Forgery checks and issue requests on user's behalf.
Details
Due to misuse of the Go net/http library, nosurf categorizes all incoming requests as plain-text HTTP requests, in which case the Referer header is not checked to have the same origin as the target webpage.
If the attacker has control over HTML contents on either the target website (e.g. example.com), or on a website hosted on a subdomain of the target (e.g. attacker.example.com), they will also be able to manipulate cookies set for the target website. By acquiring the secret CSRF token from the cookie, or overriding the cookie with a new token known to the attacker, attacker.example.com is able to craft cross-site requests to example.com.
Patches
A patch for the issue was released in nosurf 1.2.0.
Workarounds
In lieu of upgrading to a patched version of nosurf, users may additionally use another HTTP middleware to ensure that a non-safe HTTP request is coming from the same origin (e.g. by requiring a Sec-Fetch-Site: same-origin header in the request).
References
https://github.com/advisories/GHSA-rq77-p4h8-4crw https://github.com/justinas/nosurf-cve-2025-46721 https://www.cve.org/CVERecord?id=CVE-2025-46721 https://github.com/justinas/nosurf/releases/tag/v1.2.0
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/justinas/nosurf | all versions | 1.2.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/justinas/nosurf. 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 github.com/justinas/nosurf to 1.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w9hf-35q4-vcjw 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-w9hf-35q4-vcjw 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-w9hf-35q4-vcjw. 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-w9hf-35q4-vcjw in your dependencies?
O3 detects GHSA-w9hf-35q4-vcjw across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.