CVE-2026-34828
Nadh Listmonk 4.1.0 – 6.1.0
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:NSummary
CVE-2026-34828 is a high-severity Insufficient Session Expiration (CWE-613) vulnerability in Nadh Listmonk. Its CVSS base score is 7.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 22th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-12 (Session Termination) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-34828 is a session management vulnerability (CWE-613) affecting listmonk, a standalone, self-hosted newsletter and mailing list manager. The issue impacts versions from 4.1.0 up to but not including 6.1.0, where previously issued authenticated sessions remain valid even after sensitive account security changes such as password resets or password changes. This flaw undermines standard account recovery and session invalidation mechanisms, allowing persistent access via session cookies despite user-initiated security actions. The vulnerability carries a CVSS v3.1 base score of 7.1 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N), indicating high confidentiality impact with low privileges required.
An authenticated attacker with low privileges (PR:L) who has obtained a valid session cookie can exploit this vulnerability over the network with low complexity and no user interaction. Upon exploitation, the attacker retains unauthorized access to the victim's account even after the victim performs a password reset or change, bypassing expected session termination. This enables continued high-level confidentiality breaches, such as accessing sensitive mailing list data, and limited integrity modifications, while availability remains unaffected.
The listmonk security advisory (GHSA-h5j9-cvrw-v5qh) and release notes for version 6.1.0 detail the patch, implemented via commit db82035d619348949512dafdaf60c86037cafc9e, which ensures sessions are properly invalidated upon password changes or resets. Security practitioners should upgrade affected listmonk instances to version 6.1.0 or later to mitigate the issue, and review existing sessions for potential compromise by logging out all users or implementing additional session controls where feasible.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-18476
Vulnerability Data
listmonk is a standalone, self-hosted, newsletter and mailing list manager. From version 4.1.0 to before version 6.1.0, a session management vulnerability allows previously issued authenticated sessions to remain valid after sensitive account security changes, specifically password reset and password change.…
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As a result, an attacker who has already obtained a valid session cookie can retain access to the account even after the victim changes or resets their password. This weakens account recovery and session security guarantees. This issue has been patched in version 6.1.0.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
AC-12 directly requires automatic session termination after a defined period, structurally preventing reuse of expired session identifiers.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Credential lifecycle management directly includes enforcing session expiration to prevent reuse.
Authorization policy enforcement and review covers terminating stale sessions to limit access scope.
Authentication mechanisms can incorporate session timeout checks but do not inherently address expiration policy.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Automatic termination of inactive sessions and limits on connection duration shrink the window during which a hijacked or unattended authenticated session can be exploited.