CVE-2026-34828
HIGHCVE-2026-34828 is a high-severity (CVSS 7.1) CWE-613 vulnerability in github.com/knadh/listmonk. O3 Security confirms whether CVE-2026-34828 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
listmonk: Active sessions remain valid after password reset and password change
Blast Radius
github.com/knadh/listmonkReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
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. 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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/knadh/listmonk | ≥ 1.1.1-0.20241028090858-319053dd7a90&&< 1.1.1-0.20260329113754-1b5e8d38c778 | 1.1.1-0.20260329113754-1b5e8d38c778 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/knadh/listmonk. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/knadh/listmonk to 1.1.1-0.20260329113754-1b5e8d38c778 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34828 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-34828 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-34828. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-34828 in your dependencies?
O3 detects CVE-2026-34828 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.