{"id":"CVE-2026-111805","kind":"vulnerability","aliases":["CVE-2026-111805"],"related":[],"title":"Apache Traffic Server: truncated HTTP/2 Content-Length exhausts origin worker pools","description":"Apache Traffic Server can be used to exhaust an HTTP/1.1 origin's worker pool via a truncated HTTP/2 Content-Length value.\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.","summary":"Apache Traffic Server forwards a truncated Content-Length from HTTP/2 clients to HTTP/1.1 origins, which can leave origin workers waiting. An attacker can exhaust the origin's worker pool and cause denial of service.","severity":"high","cvss":8.6,"epss":0.00324,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["apache-traffic-server","http2","runtime","self-hosted"],"not_affected_if":["managed-hosting","no-http2-clients","version-outside-affected-ranges"],"how_to_check":"Check the installed Traffic Server version (traffic_server -V or the package manager) and see whether it falls in 8.0.0-8.1.11, 9.0.0-9.2.15, 10.0.0-10.1.4, or 10.2.0.","fix":"Upgrade to 9.2.16, 10.1.5, or 10.2.1, matching your major line.","status":"open","published_at":"2026-10-21T20:17:22+00:00","first_seen_at":"2026-10-23T21:57:29+00:00","triaged_at":"2026-10-23T22:39:22+00:00","updated_at":"2026-10-24T13:15:54+00:00","category":"runtime","confidence":0.7,"triage":{"at":"2026-10-23T22:39:22Z","model":"claude-haiku-5-5","output":{"fix":"Upgrade to 9.2.16, 10.1.5, or 10.2.1, matching your major line.","reach":"internet","title":"Apache Traffic Server: truncated HTTP/2 Content-Length exhausts origin worker pools","impact":"medium","summary":"Apache Traffic Server forwards a truncated Content-Length from HTTP/2 clients to HTTP/1.1 origins, which can leave origin workers waiting. An attacker can exhaust the origin's worker pool and cause denial of service.","category":"runtime","who_cares":["apache-traffic-server","http2","self-hosted"],"confidence":0.7,"needs_auth":"no","worst_case":"Origin server worker pool exhausted, causing denial of service for the origin","analyst_note":"","how_to_check":"Check the installed Traffic Server version (traffic_server -V or the package manager) and see whether it falls in 8.0.0-8.1.11, 9.0.0-9.2.15, 10.0.0-10.1.4, or 10.2.0.","needs_analyst":false,"not_affected_if":["managed-hosting","no-http2-clients","version-outside-affected-ranges"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.00052,"input_tokens":2992,"output_tokens":441,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-111805':15A,18A '-2026':14A,17A '10.0.0':100C '10.1.4':102C '10.1.5':112C '10.2.0':103C '10.2.1':114C '8.0.0':92C '8.1.11':94C '9.0.0':96C '9.2.15':98C '9.2.16':111C 'affect':87C 'apach':1A,20B,28B,63C,88C 'apache-traffic-serv':19B 'attack':50B 'caus':59B 'client':39B 'content':7A,35B,82C 'content-length':6A,34B,81C 'cve':13A,16A 'denial':60B 'exhaust':9A,52B,70C 'fix':116C 'forward':31B 'host':27B 'http/1.1':41B,72C 'http/2':5A,38B,80C 'http2':23B 'issu':86C,118C 'leav':45B 'length':8A,36B,83C 'origin':10A,42B,46B,54B,73C 'pool':12A,57B,76C 'recommend':106C 'runtim':24B 'self':26B 'self-host':25B 'server':3A,22B,30B,65C,90C 'servic':62B 'traffic':2A,21B,29B,64C,89C 'truncat':4A,33B,79C 'upgrad':108C 'use':68C 'user':104C 'valu':84C 'version':110C 'via':77C 'wait':48B 'worker':11A,47B,56B,75C","nicknames":[],"mitigations":[],"who_affected":null,"tier":"B","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-21T20:17:22+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:H/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","cvss_by":"security@apache.org","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-111805","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-111805","severity":null,"published_at":"2026-10-21T20:17:22+00:00","modified_at":"2026-10-23T22:16:55+00:00","first_seen_at":"2026-10-23T21:57:29+00:00","fetched_at":"2026-10-23T22:29:02+00:00","note":null},{"source":"epss","external_id":"CVE-2026-111805","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-111805","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-24T13:15:54+00:00","fetched_at":"2026-10-24T13:15:54+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}