Skip to main content
VulnerabilityPublished

CVE-2025-58430: knadh listmonk · Basic XSS

Affects knadh listmonkSource CVE Database V5

0

Not known to be exploited · CVSS 8.6 High.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 4.0 base score
8.6High
How severe the flaw is on the 0–10 CVSS scale.
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:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 9 Sep 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
knadh listmonkAffected
  • <=1.1.0
Fixed in–

AI-suggested

  1. Immediate mitigation should include disabling or restricting access to listmonk instances from untrusted networks to reduce exposure.
  2. 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.
  3. Enforce strict Content Security Policy (CSP) headers to limit script execution and reduce XSS impact.
  4. Conduct thorough input validation and output encoding on all user-supplied data within listmonk interfaces, especially in administrative functions.
  5. Monitor logs for unusual administrative account creation or suspicious HTTP requests containing manipulated 'nonce' parameters.
  6. Where possible, isolate listmonk instances in segmented network zones with limited access.
  7. Prepare for rapid patch deployment once vendor releases a fix; consider contributing to or monitoring vendor communications for updates.
  8. Educate administrators and users about phishing risks that could leverage this vulnerability.
  9. 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.

References

Community reviews

Loading reviews…