{"id":"CVE-2025-55702","aliases":["DEBIAN-CVE-2025-55702","EUVD-2025-211168","GHSA-5vqp-jf47-frjg","UBUNTU-CVE-2025-55702"],"status":"published","title":"Apache Traffic Server: An unread Expect: 100-continue request body is framed as a new request","description":"When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that shares connections to Traffic Server can use this to smuggle requests past the front end and desynchronize responses for other users.\n\n\n\nThis issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.\n\n\n\nUsers are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.","severity":{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00325,"percentile":0.25764,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-444"],"published":"2026-10-21T18:24:21Z","modified":"2026-10-29T09:47:35Z","affected":[{"source":"osv","ecosystem":"Debian:12","package":"trafficserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["9.2.0+ds-2","9.2.0+ds-2+deb12u1","9.2.1+ds-1","9.2.2+ds-1","9.2.3+ds-1","9.2.3+ds-1+deb12u1","9.2.4+ds-0+deb12u1","9.2.4+ds-1","9.2.4+ds-2","9.2.5+ds-0+deb12u1","9.2.5+ds-0+deb12u2","9.2.5+ds-0+deb12u3","9.2.5+ds-0+deb12u4","9.2.5+ds-1"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"trafficserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.3.0-2ubuntu1","5.3.0-2ubuntu2"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"trafficserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.0.0-5","7.1.2+ds-2","7.1.2+ds-2build1","7.1.2+ds-3"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"trafficserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.0.5+ds-1","8.0.5+ds-2","8.0.5+ds-2build1","8.0.5+ds-2ubuntu1","8.0.5+ds-3","8.0.5+ds-3ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:22.04:LTS","package":"trafficserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["8.1.1+ds-1.1","9.1.1+ds-2build1","9.1.1+ds-2ubuntu0.1~esm1","9.1.1+ds-2ubuntu0.1","9.1.1+ds-2ubuntu0.1+esm1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"trafficserver","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["9.2.1+ds-1build1","9.2.2+ds-1","9.2.3+ds-1","9.2.3+ds-1+deb12u1","9.2.3+ds-1+deb12u1build1","9.2.3+ds-1+deb12u1build3","9.2.3+ds-1+deb12u1build4","9.2.3+ds-1+deb12u1ubuntu0.1"]}],"products":[{"vendor":"apache software foundation","product":"apache traffic server"}],"references":[{"url":"https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc","tags":["vendor-advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-55702"},{"url":"https://github.com/advisories/GHSA-5vqp-jf47-frjg"},{"url":"https://security-tracker.debian.org/tracker/CVE-2025-55702","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2025-55702","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2025-55702","tags":["report"]},{"url":"https://trafficserver.apache.org/security-2026-10.html","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2025-55702","title":"Apache Traffic Server: An unread Expect: 100-continue request body is framed as a new request","description":"When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that shares connections to Traffic Server can use this to smuggle requests past the front end and desynchronize responses for other users.\n\n\n\nThis issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.\n\n\n\nUsers are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.","status":"published","published":"2026-10-21T18:24:21.377Z","modified":"2026-10-23T11:06:22.172Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T14:32:52.839698Z"}],"euvd":[{"id":"EUVD-2025-211168","description":"When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that shares connections to Traffic Server can use this to smuggle requests past the front end and desynchronize responses for other users.\n\n\n\nThis issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.\n\n\n\nUsers are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.","status":"published","published":"2026-10-21T18:24:21Z","modified":"2026-10-23T11:06:22Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","level":"high"}],"updated_at":"2026-11-02T16:59:33.058354Z"}],"ghsa":[{"id":"GHSA-5vqp-jf47-frjg","title":"When a client sends a POST with Expect: 100-continue and the origin answers before reading the...","description":"When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that shares connections to Traffic Server can use this to smuggle requests past the front end and desynchronize responses for other users.\n\n\n\nThis issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.\n\n\n\nUsers are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.","status":"published","published":"2026-10-21T21:32:31Z","modified":"2026-10-21T21:32:31Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/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","level":"high"},{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N","level":"high"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T15:14:14.355379Z"}],"nvd":[{"id":"CVE-2025-55702","description":"When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that shares connections to Traffic Server can use this to smuggle requests past the front end and desynchronize responses for other users.\n\n\n\nThis issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.\n\n\n\nUsers are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.","status":"published","published":"2026-10-21T19:16:48.12Z","modified":"2026-10-28T14:10:00.22Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/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","level":"high","assessor":"secondary"},{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-444"],"updated_at":"2026-11-02T14:12:03.20248Z"}],"osv":[{"id":"DEBIAN-CVE-2025-55702","description":"When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that shares connections to Traffic Server can use this to smuggle requests past the front end and desynchronize responses for other users.    This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0.    Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.","status":"published","published":"2026-10-21T19:16:48.12Z","modified":"2026-10-29T09:47:35.050158872Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/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","level":"high"}],"updated_at":"2026-11-02T15:45:47.378563Z"},{"id":"UBUNTU-CVE-2025-55702","description":"When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that shares connections to Traffic Server can use this to smuggle requests past the front end and desynchronize responses for other users. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.","status":"published","published":"2026-10-21T19:16:00Z","modified":"2026-10-28T20:16:12.944834331Z","cvss":[{"version":"3.1","score":8.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N","level":"high"},{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","level":"high"}],"updated_at":"2026-11-02T16:55:50.817402Z"}]}}