CVEvulnerability
CVE-2026-58055
6.3 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-06-28
- Last modified
- 2026-10-25
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 6.3 MEDIUM — CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CVSS 3.1 ([email protected])
- 5.4 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
- Weaknesses
- CWE-444
Description
nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection headers while passing Content-Length verbatim. A backend that resolves the resulting ambiguous message in the attacker's favor enables HTTP request/response smuggling and cross-client response-queue poisoning.
Affected configurations
• nghttp2 nghttp2 (<= 1.69.0)
Related
Weakness · CWE (1)
- CWE-444 Inconsistent Interpretation of HTTP Requests weakness
References
- https://github.com/bikini/exploitarium/tree/main/nghttp2-nghttpx-upgrade-queue-poison-poc Broken Link
- https://github.com/nghttp2/nghttp2/commit/ab28105c4a0197da24f8bfc414bc116055249e1e Patch
- https://www.vulncheck.com/advisories/nghttp2-nghttpx-http-request-response-smuggling-via-upgrade-request-with-content-length Patch, Third Party Advisory