GHSA-528q-4pgm-wvg2 — go-httpbin
Fix: mccutchen/go-httpbin@0decfd1GHSA-528q-4pgm-wvg2 is a CWE-80 vulnerability in github.com/mccutchen/go-httpbin. A fix is available for github.com/mccutchen/go-httpbin — see the affected versions and patch details below.
Reflected XSS in go-httpbin due to unrestricted client control over Content-Type
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-528q-4pgm-wvg2.
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.
Real-World Exposure
github.com/mccutchen/go-httpbin🐹github.com/mccutchen/go-httpbin/v2Real-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
Description
The go-httpbin framework is vulnerable to XSS as the user can control the Response Content-Type from GET parameter. This allows attacker to execute cross site scripts in victims browser.
Affected URLs:
/response-headers?Content-Type=text/html&xss=%3Cimg/src/onerror=alert(%27xss%27)%3E/base64/PGltZy9zcmMvb25lcnJvcj1hbGVydCgneHNzJyk+?content-type=text/html/base64/decode/PGltZy9zcmMvb25lcnJvcj1hbGVydCgneHNzJyk+?content-type=text/html
Steps to reproduce:
- Visit one of the above mentioned URLs.
- XSS window will popup
Suggested fix
- Allow Only Safe Content-Type Values Or give users option to define whitelisted Content-Type headers
Criticality
The following can be major impacts of the issue:
- Access to victim's sensitive Personal Identifiable Information.
- Access to CSRF token
- Cookie injection
- Phishing
- And any other thing Javascript can perform
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mccutchen/go-httpbin | all versions | 2.18.0go get github.com/mccutchen/go-httpbin@v2.18.0 |
| 🐹Go | github.com/mccutchen/go-httpbin/v2 | all versions | 2.18.0go get github.com/mccutchen/go-httpbin/v2@v2.18.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/mccutchen/go-httpbin, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/mccutchen/go-httpbin to 2.18.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-528q-4pgm-wvg2 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-528q-4pgm-wvg2 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-528q-4pgm-wvg2. 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-528q-4pgm-wvg2 in your dependencies?
O3 Security finds GHSA-528q-4pgm-wvg2 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.