CVE-2025-58430: knadh listmonk · Basic XSS
Affects knadh listmonkSource CVE Database V5
Not known to be exploited · CVSS 8.6 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 9 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| knadh listmonk | Affected
| Fixed in– |
AI-suggested
- Immediate mitigation should include disabling or restricting access to listmonk instances from untrusted networks to reduce exposure.
- Implement Web Application Firewall (WAF) rules to detect and block common XSS and CSRF attack patterns targeting listmonk endpoints, particularly filtering requests with suspicious 'nonce' parameter manipulations.
- Enforce strict Content Security Policy (CSP) headers to limit script execution and reduce XSS impact.
- Conduct thorough input validation and output encoding on all user-supplied data within listmonk interfaces, especially in administrative functions.
- Monitor logs for unusual administrative account creation or suspicious HTTP requests containing manipulated 'nonce' parameters.
- Where possible, isolate listmonk instances in segmented network zones with limited access.
- Prepare for rapid patch deployment once vendor releases a fix; consider contributing to or monitoring vendor communications for updates.
- Educate administrators and users about phishing risks that could leverage this vulnerability.
- Consider temporary alternative mailing list management solutions if risk is unacceptable until a patch is available.
Description
listmonk is a standalone, self-hosted, newsletter and mailing list manager. In versions up to and including 1.1.0, every http request in addition to the session cookie `session` there included `nonce`. The value is not checked and validated by the backend, removing `nonce` allows the requests to be processed correctly. This may seem harmless, but if chained to other vulnerabilities it can become a critical vulnerability. Cross-site request forgery and cross-site scripting chained together can result in improper admin account creation. As of time of publication, no patched versions are available.