{"identifier":"CVE-2026-88010","cve":{"id":"CVE-2026-88010","description":"Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.7.13, checkPassword in pkg/middlewares/auth/basic_auth.go constructs the BasicAuth singleflight key from the submitted password and stored secret. Concurrent requests for absent usernames therefore coalesce on one key while configured usernames perform separate password hashes, creating an unauthenticated timing discrepancy that reveals whether a username exists. Sequential checks remain cost-equalized, Traefik v2 and Digest authentication are not affected, and the issue does not disclose credentials or bypass authentication. This issue is fixed in version 3.7.13.","published":"2026-09-22T16:18:06.963000+00:00","modified":"2026-10-29T17:08:46.137000+00:00","status":"Analyzed","score":6.3,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/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","cvss_version":"4.0","affected":[{"criteria":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6.11","versionStartExcluding":"","versionEndIncluding":"","versionEndExcluding":"3.7.13"}],"weaknesses":["CWE-208"],"references":[{"url":"https://github.com/traefik/traefik/commit/ddc1bf4660b85fd61fafdd821eb8216fb1a0b130","source":"security-advisories@github.com","tags":["Patch"]},{"url":"https://github.com/traefik/traefik/pull/13816","source":"security-advisories@github.com","tags":["Issue Tracking","Patch"]},{"url":"https://github.com/traefik/traefik/releases/tag/v3.7.13","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/traefik/traefik/security/advisories/GHSA-8fcf-v89g-xpg6","source":"security-advisories@github.com","tags":["Vendor Advisory","Patch"]}],"kev":null,"kev_checked":true,"metrics":{"cvssMetricV40":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/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","baseScore":6.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":1.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-22T15:59:02.259376Z","id":"CVE-2026-88010","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*","versionStartIncluding":"3.6.11","versionEndExcluding":"3.7.13","matchCriteriaId":"0982F009-F85F-4334-8008-7EF013DBBEA1"}]}]}],"source":"nvd","retrieved_at":"2026-10-29T19:35:39.079573+00:00","exploited":false,"kev_stale":false,"products":["traefik / traefik"],"priority":{"label":"Assess exposure and vendor guidance","reasons":["No higher-priority signal is available in the current stored evidence."]},"epss":{"probability":0.00691,"percentile":0.52747,"date":"2026-10-29","stale":false},"version_assessment":null},"news":[],"campaigns":[],"domains":[{"domain":"github.com","source_url":"https://github.com/traefik/traefik/commit/ddc1bf4660b85fd61fafdd821eb8216fb1a0b130","investigate_url":"https://investigate.aeglixmind.com/#github.com"}],"arsenal_url":"https://arsenal.aeglixmind.com/?cve=CVE-2026-88010","catalog_url":"https://cves.aeglixmind.com/cve/CVE-2026-88010","research_url":"https://investigate.aeglixmind.com/research/cve/CVE-2026-88010","coverage":{"news_candidates_checked":0,"campaign_candidates_checked":0,"bounded":false,"notice":"Exact CVE mentions in stored public excerpts and reviewed campaign content only. A mention is not proof of exploitation, attribution or tool suitability. Missing matches do not establish absence."}}