{"cve":"CVE-2021-39204","nvd":{"published":"2021-09-09T22:15:09.773","modified":"2026-06-17T04:03:18.433","status":"Modified","description":"Pomerium is an open source identity-aware access proxy. Envoy, which Pomerium is based on, incorrectly handles resetting of HTTP/2 streams with excessive complexity. This can lead to high CPU utilization when a large number of streams are reset. This can result in a DoS condition. Pomerium versions 0.14.8 and 0.15.1 contain an upgraded envoy binary with this vulnerability patched.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-834"],"references":["https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc","https://github.com/pomerium/pomerium/security/advisories/GHSA-5wjf-62hw-q78r","https://groups.google.com/g/envoy-announce/c/5xBpsEZZDfE/m/wD05NZBbAgAJ","https://github.com/envoyproxy/envoy/security/advisories/GHSA-3xh3-33v5-chcc","https://github.com/pomerium/pomerium/security/advisories/GHSA-5wjf-62hw-q78r"],"products":["envoyproxy:envoy","pomerium:pomerium"],"source":"nvd","synced_at":"2026-10-19T21:23:41.316049955+00:00"},"epss":{"cve":"CVE-2021-39204","score":0.01662,"percentile":0.76698,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-5wjf-62hw-q78r","url":"https://osv.dev/vulnerability/GHSA-5wjf-62hw-q78r","summary":"Excessive CPU usage","modified":"2026-02-04T03:45:50.973535Z","packages":[{"ecosystem":"Go","name":"github.com/pomerium/pomerium","purl":"pkg:golang/github.com/pomerium/pomerium","ranges":["<0.14.8"],"fixed":["0.14.8"]},{"ecosystem":"Go","name":"github.com/pomerium/pomerium","purl":"pkg:golang/github.com/pomerium/pomerium","ranges":[">=0.15.0 <0.15.1"],"fixed":["0.15.1"]}]}],"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."]}