CVE-2026-105298Medium· 6.3▾ SunlitPingora HTTP/2 :authority and Host header mismatch enables cache poisoning and host-based access control bypass
▾ Sunlit zone — Low / medium · no exploitation signal
impact 34.7 · likelihood 0.1 · exploitation 0
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Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake. The CVSS score shown above comes from the assigning CNA record, not NVD.
Exploit-prediction probability, daily snapshots since Oct 20.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
0.4%
Last analysed / modified upstream
0.4% → 0.6%
Pingora versions prior to 0.9.0 accepted HTTP/2 requests whose Host header differed from the :authority pseudo-header. Request filters, cache keys, and logs that read the request URI (session.req_header().uri) saw the :authority value, but the upstream received the client-supplied Host value. Pingora also accepted :authority values containing userinfo (for example, [email protected]). This violates RFC 9113 Section 8.3.1, which requires an intermediary to use the :authority value for Host and replace any existing Host field.
A remote, unauthenticated attacker can send a single HTTP/2 request that the application sees as one host and the upstream receives as another. Where request filters, access controls, or cache keys use the URI authority and the upstream routes by Host, this can lead to cache poisoning, where a response from another virtual host is stored under the victim host's cache key and served to other users, or host-based access control bypass, where a request approved for one host is served by a different virtual host on the upstream. Deployments that do not accept HTTP/2 from clients, or that do not use the request authority for security or caching decisions, are not affected.
This flaw was corrected in commits 915590a91811877795531f6ba0927a3138b5cb4b and ffab8302d08d4292d1924eb8fe84647fd5cb8e76. Pingora now returns 400 Bad Request for HTTP/2 requests whose Host differs from :authority, that contain more than one Host, or whose authority contains userinfo, and keeps the upstream Host or :authority consistent with the request authority. Users should upgrade to Pingora >= 0.9.0.
Note: Cloudflare CDN customers were unaffected, as internal Pingora services at Cloudflare do not have HTTP/2 clients.
pingora-core >= 0.0.0-0, < 0.9.0Upgrade to a patched release:
pingora-core 0.9.0Connected by shared product, vendor, weakness, or advisory.