CVE-2026-21881

{"id": "CVE-2026-21881", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 3.9}]}, "published": "2026-01-08T02:15:53.803", "references": [{"url": "https://github.com/kanboard/kanboard/commit/7af6143e2ad25b5c15549cca8af4341c7ac4e2fc", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/kanboard/kanboard/releases/tag/v1.2.49", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/kanboard/kanboard/security/advisories/GHSA-wwpf-3j4p-739w", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/kanboard/kanboard/security/advisories/GHSA-wwpf-3j4p-739w", "tags": ["Exploit", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-287"}]}], "descriptions": [{"lang": "en", "value": "Kanboard is project management software focused on Kanban methodology. Versions 1.2.48 and below is vulnerable to a critical authentication bypass when REVERSE_PROXY_AUTH is enabled. The application blindly trusts HTTP headers for user authentication without verifying the request originated from a trusted reverse proxy. An attacker can impersonate any user, including administrators, by simply sending a spoofed HTTP header. This issue is fixed in version 1.2.49."}], "lastModified": "2026-01-20T15:57:22.667", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:kanboard:kanboard:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "AFA1D972-E76A-4A20-95F5-68D9915D3797", "versionEndExcluding": "1.2.49"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}