{"id":"CVE-2026-118766","kind":"vulnerability","aliases":["CVE-2026-118766"],"related":[],"title":"Botan: OCSP client redirect enables blind request to internal services","description":"Botan is a C++ cryptography library. Prior to 3.13.0, Botan's online OCSP client allowed a single HTTP redirect while posting an OCSP request to the URI in a certificate's Authority Information Access extension. A malicious OCSP responder or an on-path attacker could redirect the client to make one blind request to an otherwise unreachable internal HTTP service. The primary impact is blind SSRF that might affect internal services with non-idempotent GET handlers, and response timing can provide a coarse internal-service oracle. This issue is fixed in version 3.13.0.","summary":"Botan's online OCSP client follows one HTTP redirect when posting to a certificate's OCSP responder URI. A malicious responder or on-path attacker can make the client send one blind request to an internal HTTP service that is otherwise unreachable.","severity":"medium","cvss":6.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["botan","c++","cryptography","package","ssrf"],"not_affected_if":["no-online-ocsp-client","version-3.13.0-or-later"],"how_to_check":"- Check the Botan version with `botan --version` or in your lockfile or package manifest.\n- Look for applications that call Botan's online OCSP checking on certificates from untrusted sources.","fix":"- Botan: `3.13.0`","status":"open","published_at":"2026-10-29T18:17:28+00:00","first_seen_at":"2026-10-29T18:26:33+00:00","triaged_at":"2026-10-29T18:28:42+00:00","updated_at":"2026-10-29T18:28:42+00:00","category":"package","confidence":0.8,"triage":{"at":"2026-10-29T18:28:42Z","model":"claude-haiku-5-5","output":{"fix":"- Botan: `3.13.0`","reach":"network","title":"Botan: OCSP client redirect enables blind request to internal services","impact":"low","summary":"Botan's online OCSP client follows one HTTP redirect when posting to a certificate's OCSP responder URI. A malicious responder or on-path attacker can make the client send one blind request to an internal HTTP service that is otherwise unreachable.","audience":"developers","category":"package","nicknames":[],"who_cares":["c++","botan","cryptography","ssrf"],"confidence":0.8,"fix_status":"available","needs_auth":"no","worst_case":"Attacker triggers one blind request to an internal HTTP service","analyst_note":"","how_to_check":"- Check the Botan version with `botan --version` or in your lockfile or package manifest.\n- Look for applications that call Botan's online OCSP checking on certificates from untrusted sources.","plain_action":"","needs_analyst":false,"not_affected_if":["version-3.13.0-or-later","no-online-ocsp-client"],"who_is_affected":"Applications that link Botan older than 3.13.0 and perform online OCSP checks, where the OCSP URI comes from a certificate that may be attacker-controlled. The risk is blind server-side request forgery against internal HTTP services that are reachable from the application host but not from the internet. Teams not using Botan's online OCSP client, or running a fixed version, can skip it.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000684,"input_tokens":4192,"output_tokens":530,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-118766':13A,16A '-2026':12A,15A '3.13.0':73C,160C 'access':98C 'affect':134C 'allow':79C 'attack':47B,109C 'author':96C 'blind':6A,54B,117C,130C 'botan':1A,17B,22B,65C,74C 'c':18B,68C 'certif':35B,94C 'client':3A,26B,51B,78C,113C 'coars':149C 'could':110C 'cryptographi':19B,69C 'cve':11A,14A 'enabl':5A 'extens':99C 'fix':157C 'follow':27B 'get':141C 'handler':142C 'http':29B,59B,82C,124C 'idempot':140C 'impact':128C 'inform':97C 'intern':9A,58B,123C,135C,151C 'internal-servic':150C 'issu':155C 'librari':70C 'make':49B,115C 'malici':41B,101C 'might':133C 'non':139C 'non-idempot':138C 'ocsp':2A,25B,37B,77C,87C,102C 'on-path':44B,106C 'one':28B,53B,116C 'onlin':24B,76C 'oracl':153C 'otherwis':63B,121C 'packag':20B 'path':46B,108C 'post':32B,85C 'primari':127C 'prior':71C 'provid':147C 'redirect':4A,30B,83C,111C 'request':7A,55B,88C,118C 'respond':38B,42B,103C 'respons':144C 'send':52B 'servic':10A,60B,125C,136C,152C 'singl':81C 'ssrf':21B,131C 'time':145C 'unreach':64B,122C 'uri':39B,91C 'version':159C","nicknames":[],"mitigations":[],"who_affected":"Applications that link Botan older than 3.13.0 and perform online OCSP checks, where the OCSP URI comes from a certificate that may be attacker-controlled. The risk is blind server-side request forgery against internal HTTP services that are reachable from the application host but not from the internet. Teams not using Botan's online OCSP client, or running a fixed version, can skip it.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"first_public_at":"2026-10-29T18:17:28+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-118766","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118766","severity":null,"published_at":"2026-10-29T18:17:28+00:00","modified_at":"2026-10-29T18:17:28+00:00","first_seen_at":"2026-10-29T18:26:33+00:00","fetched_at":"2026-10-29T18:26:33+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"}