{"id":"CVE-2026-32688","aliases":["EEF-CVE-2026-32688","GHSA-q8x4-x7mp-5vg2"],"url":"https://o3.security/vulnerability/CVE-2026-32688","summary":"Atom table exhaustion via HTTP/2 :scheme pseudo-header in plug_cowboy","details":"## Summary\n\nAn unauthenticated remote denial-of-service vulnerability in `Plug.Cowboy.Conn` allows any attacker who can reach an HTTPS Plug.Cowboy listener via HTTP/2 to permanently exhaust the BEAM atom table and crash the entire Erlang VM.\n\n## Am I Affected?\n\nAll users running plug_cowboy with HTTP/2 may be affected, this includes Phoenix applications. If another HTTP adapter such as Bandit is used, then the consuming project is not affected. If the HTTP/2 endpoint is exposed directly (without a proxy) then the project will be affected. If a proxy is in use then it depends on the proxy configuration. Many proxies use HTTP/1.1 internally, and would be unaffected.\n\n## Impact\n\nThe vulnerability will allow crashing the Erlang VM (BEAM) via atom exhaustion.\n\n## Mitigation\n\nUsers are advised to update to plug_cowboy v2.8.1 to mitigate this issue.\n\n## Credits\nPlug.Cowboy thanks Peter Ullrich for finding and responsibly disclosing this vulnerability.","published":"2026-04-27T13:45:35.160Z","modified":"2026-08-12T03:51:26.200472791Z","cvss":null,"epss":{"score":0.00545,"percentile":0.4299,"asOf":"2026-08-13"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Hex","name":"plug_cowboy","fixedVersion":"2.8.1"}],"fix":{"url":"https://github.com/elixir-plug/plug_cowboy/commit/bfb34cb45eb354e56437f7023fb306de1bf9c19b","label":"elixir-plug/plug_cowboy@bfb34cb"},"references":[{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-32688.html"},{"type":"WEB","url":"https://github.com"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-32688"},{"type":"WEB","url":"https://repo.hex.pm"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/32xxx/CVE-2026-32688.json"},{"type":"ADVISORY","url":"https://github.com/elixir-plug/plug_cowboy/security/advisories/GHSA-q8x4-x7mp-5vg2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-32688"},{"type":"FIX","url":"https://github.com/elixir-plug/plug_cowboy/commit/bfb34cb45eb354e56437f7023fb306de1bf9c19b"},{"type":"PACKAGE","url":"https://github.com/elixir-plug/plug_cowboy"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:26.200472791Z"}}