{"answers":{"affected":"5 open source packages ship an affected version, including github.com/knadh/listmonk. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-21483 exists.","fix":"Upgrade github.com/knadh/listmonk to a fixed version for your release line: 1.1.1-0.20251231125615-74dc5a01cfbb or 6.0.0.","what":"CVE-2026-21483 is a medium-severity cross-site scripting vulnerability in knadh listmonk, published on 2 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-21483 and fix it if it is affected.\n\nWhat it is: CVE-2026-21483 is a medium-severity cross-site scripting vulnerability in knadh listmonk, published on 2 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-21483 exists.\n\nAffected packages and fixed versions:\n- github.com/knadh/listmonk (Go): affected all versions; fixed in 1.1.1-0.20251231125615-74dc5a01cfbb\n- github.com/knadh/listmonk (Go): affected all versions; fixed in 1.1.1-0.20251231125615-74dc5a01cfbb\n- github.com/knadh/listmonk (Go): affected all versions; fixed in 1.1.1-0.20251231125615-74dc5a01cfbb\n- github.com/knadh/listmonk (Go): affected from 1.1.1; fixed in 6.0.0\n- github.com/knadh/listmonk (Go): affected from 1.1.1; fixed in 6.0.0\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-21483/ (Markdown: https://insights.sbomify.com/CVE-2026-21483/index.md)","id":"CVE-2026-21483","markdown":"https://insights.sbomify.com/CVE-2026-21483/index.md","name":"CVE-2026-21483","record":{"aliases":["GHSA-jmr4-p576-v565","GO-2026-4277"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["account_takeover","privilege_escalation"],"network_reachable":"yes","non_default_config":false,"product_category":"Newsletter manager","requires_auth":"low_privilege","summary":"Lower-privileged users can inject JavaScript into campaigns, leading to admin account takeover when super admins view the content.","user_interaction":"not_required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"listmonk","vendor":"nadh"}],"cvss":{"score":5.4,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:P","version":"4.0"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"listmonk is a standalone, self-hosted, newsletter and mailing list manager. Prior to version 6.0.0, lower-privileged user with campaign management permissions can inject malicious JavaScript into campaigns or templates. When a higher-privileged user (Super Admin) views or previews this content, the XSS executes in their browser context, allowing the attacker to perform privileged actions such as creating backdoor admin accounts. The attack can be weaponized via the public archive feature, where victims simply need to visit a link - no preview click required. Version 6.0.0 fixes the issue.","ecosystems":["Go"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"listmonk Vulnerable to Stored XSS Leading to Admin Account Takeover","id":"CVE-2026-21483","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":5,"n_references":1,"next":{"headline":"AnythingLLM Vulnerable to Username Enumeration w/ Password Recovery","id":"CVE-2026-21484"},"packages":[{"ecosystem":"Go","fixed":["1.1.1-0.20251231125615-74dc5a01cfbb"],"introduced":["0"],"last_affected":[],"package":"github.com/knadh/listmonk","purl":null,"source":"GHSA-jmr4-p576-v565"},{"ecosystem":"Go","fixed":["1.1.1-0.20251231125615-74dc5a01cfbb"],"introduced":["0"],"last_affected":[],"package":"github.com/knadh/listmonk","purl":"pkg:golang/github.com/knadh/listmonk","source":"GHSA-jmr4-p576-v565"},{"ecosystem":"Go","fixed":["1.1.1-0.20251231125615-74dc5a01cfbb"],"introduced":["0"],"last_affected":[],"package":"github.com/knadh/listmonk","purl":"pkg:golang/github.com/knadh/listmonk","source":"GO-2026-4277"},{"ecosystem":"Go","fixed":["6.0.0"],"introduced":["1.1.1"],"last_affected":[],"package":"github.com/knadh/listmonk","purl":null,"source":"GHSA-jmr4-p576-v565"},{"ecosystem":"Go","fixed":["6.0.0"],"introduced":["1.1.1"],"last_affected":[],"package":"github.com/knadh/listmonk","purl":"pkg:golang/github.com/knadh/listmonk","source":"GHSA-jmr4-p576-v565"}],"prev":{"headline":"MessagePack for Java Vulnerable to Remote DoS via Malicious EXT Payload Allocation","id":"CVE-2026-21452"},"products":["listmonk"],"published":"2026-01-02","related":[{"cvss_score":9.1,"headline":"listmonk's Sprig template Injection vulnerability leads to reading of Environment Variable for low privilege user","id":"CVE-2025-49136","kev_date_added":null,"published":"2025-06-09"},{"cvss_score":8.6,"headline":"listmonk Vulnerable to CSRF to XSS Chain That Can Lead to Admin Account Takeover","id":"CVE-2025-58430","kev_date_added":null,"published":"2025-09-09"},{"cvss_score":7.1,"headline":"listmonk: Active sessions remain valid after password reset and password change","id":"CVE-2026-34828","kev_date_added":null,"published":"2026-04-02"},{"cvss_score":6.5,"headline":"SQL injection in n/a","id":"CVE-2025-46011","kev_date_added":null,"published":"2025-06-04"},{"cvss_score":5.4,"headline":"listmonk: Broken Access Control in CSV Import (Unauthorized List Assignment)","id":"CVE-2026-34584","kev_date_added":null,"published":"2026-04-02"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"Go Vulnerability Database","prefix":"GO"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-01-02","vendors":["knadh"]},"summary":"Lower-privileged users can inject JavaScript into campaigns, leading to admin account takeover when super admins view the content.","url":"https://insights.sbomify.com/CVE-2026-21483/"}