{"id":"CVE-2026-123798","kind":"vulnerability","aliases":["CVE-2026-123798"],"related":[],"title":"SuperTokens Core: SAML signature check lets attackers log in as other users","description":"SuperTokens Core is an open source authentication server. From 11.3.0 until 11.3.7, 11.4.7, and 12.0.10, SAML.verifySamlResponseSignature calls OpenSAML SignatureValidator.validate without first applying SAMLSignatureProfileValidator. The Core can therefore accept a cryptographically valid signature that references a different XML element from the Response or Assertion whose NameID and attributes are used for authentication. An ordinary user of the configured identity provider can move a genuinely signed element elsewhere in the document while supplying an attacker-authored identity-bearing element, causing XML Signature Wrapping authentication as another IdP user. Both response-level and assertion-level signing paths are affected, and SP-initiated login remains reachable without enabling allowIDPInitiatedLogin. This issue is fixed in versions 11.3.7, 11.4.7, and 12.0.10.","summary":"SuperTokens Core accepts a validly signed SAML response without confirming that the signed element is the one used for login. A user of the configured identity provider can wrap a signed element and supply their own identity, which authenticates them as another user.","severity":"high","cvss":8.1,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"SuperTokens Core","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["runtime","saml","self-hosted","supertokens-core"],"not_affected_if":["patched-version","saml-not-used"],"how_to_check":null,"fix":"- Upgrade to `11.3.7`, `11.4.7`, or `12.0.10`, matching your release line.","status":"open","published_at":"2026-11-09T19:16:46+00:00","first_seen_at":"2026-11-09T19:28:14+00:00","triaged_at":"2026-11-09T19:29:43+00:00","updated_at":"2026-11-09T19:29:43+00:00","category":"runtime","confidence":0.8,"triage":{"at":"2026-11-09T19:29:43Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade to `11.3.7`, `11.4.7`, or `12.0.10`, matching your release line.","reach":"internet","title":"SuperTokens Core: SAML signature check lets attackers log in as other users","impact":"high","summary":"SuperTokens Core accepts a validly signed SAML response without confirming that the signed element is the one used for login. A user of the configured identity provider can wrap a signed element and supply their own identity, which authenticates them as another user.","audience":"businesses","category":"runtime","nicknames":[],"who_cares":["supertokens-core","saml","self-hosted"],"confidence":0.8,"fix_status":"available","needs_auth":"yes","worst_case":"Attacker logs in as another identity provider user","analyst_note":"","how_to_check":"- Check the installed SuperTokens Core version against the affected ranges: `11.3.0` to before `11.3.7`, `11.4.x` before `11.4.7`, and `12.0.0` to before `12.0.10`.\n- Confirm whether SAML sign-in is enabled in your SuperTokens configuration.","plain_action":"","product_name":"SuperTokens Core","needs_analyst":false,"not_affected_if":["saml-not-used","patched-version"],"who_is_affected":"Any application that uses SuperTokens Core with SAML single sign-on is exposed, and the risk comes from anyone with an account at the configured identity provider. Both response-level and assertion-level signing are affected, and SP-initiated login is reachable without enabling allowIDPInitiatedLogin. Teams that do not use SAML, or that run a fixed version, can skip it.","user_interaction":"no","product_ecosystem":"vendor","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.001262,"input_tokens":4833,"output_tokens":1557,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-123798':15A,18A '-2026':14A,17A '11.3.0':81C '11.3.7':83C,188C '11.4.7':84C,189C '12.0.10':86C,191C 'accept':31B,99C 'affect':171C 'allowidpinitiatedlogin':181C 'anoth':70B,157C 'appli':93C 'assert':114C,166C 'assertion-level':165C 'attack':7A,145C 'attacker-author':144C 'attribut':118C 'authent':67B,78C,122C,155C 'author':146C 'bear':149C 'call':88C 'caus':151C 'check':5A 'configur':53B,128C 'confirm':38B 'core':2A,20A,28B,30B,73C,96C 'cryptograph':101C 'cve':13A,16A 'differ':107C 'document':140C 'element':42B,60B,109C,136C,150C 'elsewher':137C 'enabl':180C 'first':92C 'fix':185C 'genuin':134C 'host':25B 'ident':54B,65B,129C,148C 'identity-bear':147C 'idp':158C 'initi':175C 'issu':183C 'let':6A 'level':163C,167C 'log':8A 'login':48B,176C 'move':132C 'nameid':116C 'one':45B 'open':76C 'opensaml':89C 'ordinari':124C 'path':169C 'provid':55B,130C 'reachabl':178C 'refer':105C 'remain':177C 'respons':36B,112C,162C 'response-level':161C 'runtim':21B 'saml':3A,22B,35B 'saml.verifysamlresponsesignature':87C 'samlsignatureprofilevalid':94C 'self':24B 'self-host':23B 'server':79C 'sign':34B,41B,59B,135C,168C 'signatur':4A,103C,153C 'signaturevalidator.validate':90C 'sourc':77C 'sp':174C 'sp-initi':173C 'supertoken':1A,27B,29B,72C 'supertokens':19A 'supertokens-cor':26B 'suppli':62B,142C 'therefor':98C 'use':46B,120C 'user':12A,50B,71B,125C,159C 'valid':33B,102C 'version':187C 'whose':115C 'without':37B,91C,179C 'wrap':57B,154C 'xml':108C,152C","nicknames":[],"mitigations":[],"who_affected":"Any application that uses SuperTokens Core with SAML single sign-on is exposed, and the risk comes from anyone with an account at the configured identity provider. Both response-level and assertion-level signing are affected, and SP-initiated login is reachable without enabling allowIDPInitiatedLogin. Teams that do not use SAML, or that run a fixed version, can skip it.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":["core","supertokenscore"],"ptokens":["core","supertokens"],"labels":["high","runtime","saml","selfhosted","supertokenscore","vendor"],"campaign_type":null,"search_a":"'-123798':15A,18A '-2026':14A,17A 'attack':7A 'check':5A 'core':2A,20A 'cve':13A,16A 'let':6A 'log':8A 'saml':3A 'signatur':4A 'supertoken':1A 'supertokens':19A 'user':12A","search_b":"'accept':31B 'anoth':70B 'authent':67B 'configur':53B 'confirm':38B 'core':28B,30B 'element':42B,60B 'host':25B 'ident':54B,65B 'login':48B 'one':45B 'provid':55B 'respons':36B 'runtim':21B 'saml':22B,35B 'self':24B 'self-host':23B 'sign':34B,41B,59B 'supertoken':27B,29B 'supertokens-cor':26B 'suppli':62B 'use':46B 'user':50B,71B 'valid':33B 'without':37B 'wrap':57B","search_c":"'11.3.0':81C '11.3.7':83C,188C '11.4.7':84C,189C '12.0.10':86C,191C 'accept':99C 'affect':171C 'allowidpinitiatedlogin':181C 'anoth':157C 'appli':93C 'assert':114C,166C 'assertion-level':165C 'attack':145C 'attacker-author':144C 'attribut':118C 'authent':78C,122C,155C 'author':146C 'bear':149C 'call':88C 'caus':151C 'configur':128C 'core':73C,96C 'cryptograph':101C 'differ':107C 'document':140C 'element':109C,136C,150C 'elsewher':137C 'enabl':180C 'first':92C 'fix':185C 'genuin':134C 'ident':129C,148C 'identity-bear':147C 'idp':158C 'initi':175C 'issu':183C 'level':163C,167C 'login':176C 'move':132C 'nameid':116C 'open':76C 'opensaml':89C 'ordinari':124C 'path':169C 'provid':130C 'reachabl':178C 'refer':105C 'remain':177C 'respons':112C,162C 'response-level':161C 'saml.verifysamlresponsesignature':87C 'samlsignatureprofilevalid':94C 'server':79C 'sign':135C,168C 'signatur':103C,153C 'signaturevalidator.validate':90C 'sourc':77C 'sp':174C 'sp-initi':173C 'supertoken':72C 'suppli':142C 'therefor':98C 'use':120C 'user':125C,159C 'valid':102C 'version':187C 'whose':115C 'without':91C,179C 'wrap':154C 'xml':108C,152C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-10-16T13:03:27+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-123798","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123798","severity":null,"published_at":"2026-11-09T19:16:46+00:00","modified_at":"2026-11-09T19:16:46+00:00","first_seen_at":"2026-11-09T19:28:14+00:00","fetched_at":"2026-11-09T19:28:14+00:00","note":null}],"documents":[{"id":109099,"url":"https://github.com/supertokens/supertokens-core/commit/8d06b0cfb5409c5bf505051ddfcb94d66367caae","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":109100,"url":"https://github.com/supertokens/supertokens-core/commit/9cba541ae2ed87b878d11b257bc9b8b78341f50a","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":109101,"url":"https://github.com/supertokens/supertokens-core/commit/d0773f2a6497411aeda5d4f03d3d135a2a3ae79c","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":109102,"url":"https://github.com/supertokens/supertokens-core/releases/tag/v11.3.7","title":"Release notes: github.com","kind":"release","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Release notes: github.com"},{"id":109103,"url":"https://github.com/supertokens/supertokens-core/releases/tag/v11.4.7","title":"Release notes: github.com","kind":"release","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Release notes: github.com"},{"id":109104,"url":"https://github.com/supertokens/supertokens-core/releases/tag/v12.0.10","title":"Release notes: github.com","kind":"release","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Release notes: github.com"},{"id":109105,"url":"https://github.com/supertokens/supertokens-core/security/advisories/GHSA-gvx2-mwmj-wwvj","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-16T13:03:27+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"}],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}