{"answers":{"affected":"It affects 2 products.","exploited":"There is no known exploitation of CVE-2026-4721 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-4721 is a critical memory corruption vulnerability in Mozilla Firefox, published on 24 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-4721 and fix it if it is affected.\n\nWhat it is: CVE-2026-4721 is a critical memory corruption vulnerability in Mozilla Firefox, published on 24 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-4721 in the wild and no public exploit code.\n\nAffected product: Mozilla Firefox. 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-2026-4721/ (Markdown: https://insights.sbomify.com/CVE-2026-4721/index.md)","id":"CVE-2026-4721","markdown":"https://insights.sbomify.com/CVE-2026-4721/index.md","name":"CVE-2026-4721","record":{"aliases":["DEBIAN-CVE-2026-4721","GHSA-mmvq-h6g9-8h39","UBUNTU-CVE-2026-4721"],"analysis":{"component_type":"browser","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Mozilla Firefox","requires_auth":"none","summary":"Memory safety bugs in Firefox and Thunderbird allow arbitrary code execution, requiring users to upgrade to the latest versions.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mozilla","cpe":[{"product":"firefox","vendor":"mozilla"},{"product":"thunderbird","vendor":"mozilla"}],"cvss":{"score":9.8,"severity":"critical","source":"cisa-adp","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-825","name":"Expired Pointer Dereference"},{"id":"CWE-120","name":"Buffer Copy without Checking Size of Input"}],"description":"Memory safety bugs present in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.","ecosystems":[],"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":"Memory corruption in Firefox","id":"CVE-2026-4721","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"mozilla:firefox","products":["mozilla:firefox","mozilla:thunderbird"],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":6,"next":{"headline":"Privilege escalation in the IPC component","id":"CVE-2026-4722"},"packages":[],"prev":{"headline":"Memory safety bugs fixed in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149","id":"CVE-2026-4720"},"products":["Firefox","Thunderbird"],"published":"2026-03-24","related":[{"cvss_score":10,"headline":"Mozilla Firefox and Thunderbird Sandbox Escape","id":"CVE-2019-11708","kev_date_added":"2022-05-23","published":"2019-07-23"},{"cvss_score":9.8,"headline":"Mozilla Multiple Products Remote Code Execution","id":"CVE-2010-3765","kev_date_added":"2025-10-06","published":"2010-10-27"},{"cvss_score":9.6,"headline":"Mozilla Firefox Use-After-Free","id":"CVE-2022-26486","kev_date_added":"2022-03-07","published":"2022-12-22"},{"cvss_score":8.8,"headline":"Mozilla Firefox Use-After-Free","id":"CVE-2022-26485","kev_date_added":"2022-03-07","published":"2022-12-22"},{"cvss_score":8.8,"headline":"Mozilla Firefox and Thunderbird Type Confusion","id":"CVE-2019-11707","kev_date_added":"2022-05-23","published":"2019-07-23"},{"cvss_score":8.1,"headline":"Mozilla Firefox And Thunderbird Use-After-Free","id":"CVE-2020-6819","kev_date_added":"2021-11-03","published":"2020-04-24"},{"cvss_score":8.1,"headline":"Mozilla Firefox And Thunderbird Use-After-Free","id":"CVE-2020-6820","kev_date_added":"2021-11-03","published":"2020-04-24"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"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":"total"},"state":"PUBLISHED","updated":"2026-07-15","vendors":["Mozilla"]},"summary":"Memory safety bugs in Firefox and Thunderbird allow arbitrary code execution, requiring users to upgrade to the latest versions.","url":"https://insights.sbomify.com/CVE-2026-4721/"}