# CVE-2026-21483: GO-2026-4277 - listmonk Vulnerable to Stored XSS Leading to Admin Account Takeover in github.com/knadh/listmonk

Source: https://junglewise.ai/threats/cve-2026-21483-listmonk-vulnerable-to-stored-xss-leading-to-admin-account  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-01-12  
License: CC BY 4.0 with a link back

CVE-2026-21483 · Severity: medium · CVSS 4 · Published 2026-01-12

listmonk Vulnerable to Stored XSS Leading to Admin Account Takeover in github.com/knadh/listmonk

Technologies: [github.com/knadh/listmonk (Go)](https://junglewise.ai/threats/technologies/github-com-knadh-listmonk). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-21483 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-21483 being exploited in the wild.

**How severe is CVE-2026-21483?** Medium severity, with a CVSS score of 4, published 12 January 2026.

**Which products and versions are affected?** github.com/knadh/listmonk (Go) SEMVER:introduced=0,fixed=1.1.1-0.20251231125615-74dc5a01cfbb, SEMVER:introduced=1.1.1,fixed=6.0.0.

**Is there a fix for CVE-2026-21483?** Yes. github.com/knadh/listmonk (Go): upgrade to 1.1.1-0.20251231125615-74dc5a01cfbb, 6.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-21483?** Check whether you run github.com/knadh/listmonk (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/knadh/listmonk (Go): upgrade to 1.1.1-0.20251231125615-74dc5a01cfbb, 6.0.0 or later

  ```sh
  go get github.com/knadh/listmonk@v6.0.0
  ```


## Affected products

- github.com/knadh/listmonk (Go) SEMVER:introduced=0,fixed=1.1.1-0.20251231125615-74dc5a01cfbb, SEMVER:introduced=1.1.1,fixed=6.0.0

## Identifiers

- CVE-2026-21483
- GHSA-jmr4-p576-v565
- GO-2026-4277

## Related threats

- [knadh listmonk SQL injection in subscriber export endpoint](https://junglewise.ai/threats/cve-2026-62361-knadh-listmonk-sql-injection-in-subscriber-export-endpoint)
- [knadh listmonk insufficient session expiration after password change](https://junglewise.ai/threats/cve-2026-34828-knadh-listmonk-insufficient-session-expiration-after-password)
- [GO-2025-3943 - listmonk: CSRF to XSS Chain can Lead to Admin Account Takeover in github.com/knadh/listmonk](https://junglewise.ai/threats/cve-2025-58430-listmonk-csrf-to-xss-chain-can-lead-to-admin-account-takeover)
- [listmonk's Sprig template Injection vulnerability leads to reading of Environment Variable for low privilege user](https://junglewise.ai/threats/cve-2025-49136-listmonk-s-sprig-template-injection-vulnerability-leads-to)