{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-16049 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-16049 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-16049 is a low-severity missing authorization vulnerability in Mattermost, published on 17 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-16049 and fix it if it is affected.\n\nWhat it is: CVE-2026-16049 is a low-severity missing authorization vulnerability in Mattermost, published on 17 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-16049 in the wild and no public exploit code.\n\nAffected product: Mattermost. No package-level version data is available, so check the vendor advisory linked from the reference page.\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-2026-16049/ (Markdown: https://insights.sbomify.com/CVE-2026-16049/index.md)","id":"CVE-2026-16049","markdown":"https://insights.sbomify.com/CVE-2026-16049/index.md","name":"CVE-2026-16049","record":{"aliases":["GHSA-vr3j-2q9w-h26r"],"analysis":{"component_type":"cms_plugin","fix_type":"upgrade","impacts":["data_modify","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Mattermost GitLab plugin","requires_auth":"low_privilege","summary":"Authenticated attackers can inject bot messages with arbitrary URLs into unauthorized channels via missing permission checks in the GitLab plugin.","user_interaction":"not_required","vuln_class":"missing_authorization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Mattermost","cpe":[],"cvss":{"score":3.9,"severity":"low","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-862","name":"Missing Authorization"}],"description":"Mattermost Plugins versions \u003c=11.8 10.20.11 11.5.7.0 _The Mattermost GitLab plugin fails to verify channel permissions when processing API requests with a caller-supplied_ {{post_id}}_, and fails to validate the_ {{web_url}} _parameter against the configured GitLab instance, which allows an authenticated attacker to inject bot-authored messages containing arbitrary URLs into channels they do not have access to via the_ {{createIssue}} _and_ {{attachCommentToIssue}} _API endpoints._ Mattermost Advisory ID: MMSA-2026-00673","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":null,"headline":"Missing authorization in Mattermost","id":"CVE-2026-16049","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"missing_authorization","year":"2026"},"n_packages":0,"n_references":1,"next":{"headline":"WPMU DEV Dashboard \u003c 5.0.1 - Remote Code Execution via Hub Install Action","id":"CVE-2026-16051"},"packages":[],"prev":{"headline":"Channel member roles accept out-of-scope roles","id":"CVE-2026-16048"},"products":["Mattermost"],"published":"2026-08-17","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-17","vendors":["Mattermost"]},"summary":"Authenticated attackers can inject bot messages with arbitrary URLs into unauthorized channels via missing permission checks in the GitLab plugin.","url":"https://insights.sbomify.com/CVE-2026-16049/"}