{"cve":"CVE-2026-2836","nvd":{"published":"2026-03-05T00:15:58.053","modified":"2026-06-17T10:31:51.633","status":"Analyzed","description":"A cache poisoning vulnerability has been found in the Pingora HTTP proxy framework’s default cache key construction. The issue occurs because the default HTTP cache key implementation generates cache keys using only the URI path, excluding critical factors such as the host header (authority). Operators relying on the default are vulnerable to cache poisoning, and cross-origin responses may be improperly served to users.\n\n\nImpact\n\nThis vulnerability affects users of Pingora's alpha proxy caching feature who relied on the default CacheKey implementation. An attacker could exploit this for:\n\n  *  Cross-tenant data leakage: In multi-tenant deployments, poison the cache so that users from one tenant receive cached responses from another tenant\n\n\n  *  Cache poisoning attacks: Serve malicious content to legitimate users by poisoning shared cache entries\n\n\n\n\nCloudflare's CDN infrastructure was not affected by this vulnerability, as Cloudflare's default cache key implementation uses multiple factors to prevent cache key poisoning and never made use of the previously provided default.\n\n\nMitigation:\n\nWe strongly recommend Pingora users to upgrade to Pingora v0.8.0 or higher, which removes the insecure default cache key implementation. Users must now explicitly implement their own callback that includes appropriate factors such as Host header, origin server HTTP scheme, and other attributes their cache should vary on.\n\n\nPingora users on previous versions may also remove any of their default CacheKey usage and implement their own that should at minimum include the host header / authority and upstream peer’s HTTP scheme.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N","score":8.4},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","score":8.1},"cwes":["CWE-345"],"references":["https://github.com/cloudflare/pingora"],"products":["cloudflare:pingora"],"source":"nvd","synced_at":"2026-10-19T22:24:17.937441719+00:00"},"epss":{"cve":"CVE-2026-2836","score":0.00396,"percentile":0.33798,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-f93w-pcj3-rggc","url":"https://osv.dev/vulnerability/GHSA-f93w-pcj3-rggc","summary":"Pingora vulnerable to cache poisoning via insecure-by-default cache key","modified":"2026-03-09T21:02:24.914549Z","packages":[{"ecosystem":"crates.io","name":"pingora-cache","purl":"pkg:cargo/pingora-cache","ranges":["<0.8.0"],"fixed":["0.8.0"]}]},{"id":"RUSTSEC-2026-0035","url":"https://osv.dev/vulnerability/RUSTSEC-2026-0035","summary":"Cache poisoning via insecure-by-default cache key","modified":"2026-03-09T21:00:08.887295Z","packages":[{"ecosystem":"crates.io","name":"pingora-cache","purl":"pkg:cargo/pingora-cache","ranges":[">=0.0.0-0 <0.8.0"],"fixed":["0.8.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}