CVE-2026-33805
CVE-2026-33805 · @fastify/reply-from vulnerable to connection header abuse enabling stripping of proxy-added headers
This page contains facts from public vulnerability sources. Check the original advisory before updating.
@fastify/reply-from v12.6.1 and earlier and @fastify/http-proxy v11.4.3 and earlier process the client's Connection header after the proxy has added its own headers via rewriteRequestHeaders. This allows attackers to retroactively strip proxy-added headers from upstream requests by listing them in the Connection header value. Any header added by the proxy for routing, access control, or security purposes can be selectively removed by a client. @fastify/http-proxy is also affected as it delegates to @fastify/reply-from. Upgrade to @fastify/reply-from v12.6.2 or @fastify/http-proxy v11.4.4 or later.
CVSS 9.0 · Critical · EPSS 0.4% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
@fastify/reply-from
- Versions
- ≥ 0, < 12.6.2: Affected (semver)
- 12.6.2: Not affected (semver)
Update to 12.6.2
@fastify/http-proxy
- Versions
- ≥ 0, < 11.4.4: Affected (semver)
- 11.4.4: Not affected (semver)
Update to 11.4.4
@fastify/reply-from npm
- Affected ranges
- SEMVER: < 12.6.2
Update to 12.6.2
@fastify/http-proxy npm
- Affected ranges
- SEMVER: < 11.4.4
Update to 11.4.4
Original sources
- https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-gwhp-pf74-vj37
- https://cna.openjsf.org/security-advisories.html
- https://access.redhat.com/security/cve/CVE-2026-33805
- https://bugzilla.redhat.com/show_bug.cgi?id=2458651
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33805.json
- https://access.redhat.com/errata/RHSA-2026:10175
- https://nvd.nist.gov/vuln/detail/CVE-2026-33805