{"answers":{"affected":"5 open source packages ship an affected version, including github.com/mattermost/mattermost-server. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-4053 in the wild and no public exploit code.","fix":"Upgrade github.com/mattermost/mattermost-server to a fixed version for your release line: 0.0.0-20260414103857-b21ef302025e, 11.5.2+incompatible or 11.5.2.","what":"CVE-2026-4053 is a low-severity vulnerability in Mattermost Mattermost Server, published on 15 May 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-4053 and fix it if it is affected.\n\nWhat it is: CVE-2026-4053 is a low-severity vulnerability in Mattermost Mattermost Server, published on 15 May 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-2026-4053 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- github.com/mattermost/mattermost-server (Go): affected from 0.0.0-20250731163400-5b955468ea1e; fixed in 0.0.0-20260414103857-b21ef302025e, 11.5.2+incompatible\n- github.com/mattermost/mattermost-server (Go): affected from 0.0.0-20250731163400-5b955468ea1e; fixed in 0.0.0-20260414103857-b21ef302025e\n- github.com/mattermost/mattermost-server (Go): affected from 0.0.0-20250731163400-5b955468ea1e; fixed in 0.0.0-20260414103857-b21ef302025e\n- github.com/mattermost/mattermost-server (Go): affected from 11.5.0; fixed in 11.5.2\n- github.com/mattermost/mattermost-server (Go): affected from 11.5.0; fixed in 11.5.2\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-2026-4053/ (Markdown: https://insights.sbomify.com/CVE-2026-4053/index.md)","id":"CVE-2026-4053","markdown":"https://insights.sbomify.com/CVE-2026-4053/index.md","name":"CVE-2026-4053","record":{"aliases":["GHSA-hw87-6jcq-9f8q","GO-2026-5442"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["data_modify"],"network_reachable":"yes","non_default_config":false,"product_category":"Mattermost chat platform","requires_auth":"low_privilege","summary":"Authenticated users can bypass post edit time limits to modify file attachments and properties after the allowed window expires.","user_interaction":"not_required","vuln_class":"business_logic"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Mattermost","cpe":[{"product":"mattermost_server","vendor":"mattermost"}],"cvss":{"score":3.1,"severity":"low","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-672","name":"Operation on a Resource after Expiration or Release"}],"description":"Mattermost versions 11.5.x \u003c= 11.5.1, 10.11.x \u003c= 10.11.13 fail to enforce the PostEditTimeLimit on non-message post fields which allows an authenticated user to modify post file attachments, props, and pin status after the edit window has expired via the post patch and update API endpoints.. Mattermost Advisory ID: MMSA-2026-00631","ecosystems":["Go"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"post edit time limit is not enforced on some post update operations","id":"CVE-2026-4053","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":"mattermost:mattermost_server","products":["mattermost:mattermost_server"],"type":"business_logic","year":"2026"},"n_packages":5,"n_references":1,"next":{"headline":"Mattermost doesn't validate the response body of proxied images","id":"CVE-2026-4054"},"packages":[{"ecosystem":"Go","fixed":["0.0.0-20260414103857-b21ef302025e","11.5.2+incompatible"],"introduced":["0.0.0-20250731163400-5b955468ea1e","11.5.0+incompatible"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GO-2026-5442"},{"ecosystem":"Go","fixed":["0.0.0-20260414103857-b21ef302025e"],"introduced":["0.0.0-20250731163400-5b955468ea1e"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-hw87-6jcq-9f8q"},{"ecosystem":"Go","fixed":["0.0.0-20260414103857-b21ef302025e"],"introduced":["0.0.0-20250731163400-5b955468ea1e"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-hw87-6jcq-9f8q"},{"ecosystem":"Go","fixed":["11.5.2"],"introduced":["11.5.0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":null,"source":"GHSA-hw87-6jcq-9f8q"},{"ecosystem":"Go","fixed":["11.5.2"],"introduced":["11.5.0"],"last_affected":[],"package":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","source":"GHSA-hw87-6jcq-9f8q"}],"prev":{"headline":"IBM Engineering Lifecycle Management - Jazz Foundation is vulnerable to Server Post-Auth Remote Code Execution","id":"CVE-2026-4051"},"products":["Mattermost"],"published":"2026-05-15","related":[{"cvss_score":9.9,"headline":"Account takeover on OAuth/OpenID-enabled servers","id":"CVE-2025-12419","kev_date_added":null,"published":"2025-11-27"},{"cvss_score":9.9,"headline":"Account Takeover via Code Exchange Endpoint","id":"CVE-2025-12421","kev_date_added":null,"published":"2025-11-27"},{"cvss_score":9.9,"headline":"Path Traversal Leading to RCE by Any Authenticated Mattermost User","id":"CVE-2025-4981","kev_date_added":null,"published":"2025-06-20"},{"cvss_score":9.9,"headline":"Arbitrary file read via block duplication in Mattermost Boards","id":"CVE-2025-20051","kev_date_added":null,"published":"2025-02-24"},{"cvss_score":9.9,"headline":"Arbitrary file read in Mattermost Boards via import \u0026 export board archive","id":"CVE-2025-25279","kev_date_added":null,"published":"2025-02-24"},{"cvss_score":9.8,"headline":"Mattermost Server: Insufficient Password-Reset Link Invalidation","id":"CVE-2016-11074","kev_date_added":null,"published":"2020-06-19"},{"cvss_score":9.8,"headline":"Mattermost Server allows attackers to gain privileges by accessing unintended API endpoints with users' credentials","id":"CVE-2017-18885","kev_date_added":null,"published":"2020-06-19"}],"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-15","vendors":["Mattermost"]},"summary":"Authenticated users can bypass post edit time limits to modify file attachments and properties after the allowed window expires.","url":"https://insights.sbomify.com/CVE-2026-4053/"}