{"answers":{"affected":"It affects 3 products.","exploited":"There is no known exploitation of CVE-2020-26959 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2020-26959 is a high-severity use after free vulnerability in Mozilla Firefox, published on 9 Dec 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2020-26959 and fix it if it is affected.\n\nWhat it is: CVE-2020-26959 is a high-severity use after free vulnerability in Mozilla Firefox, published on 9 Dec 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2020-26959 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-2020-26959/ (Markdown: https://insights.sbomify.com/CVE-2020-26959/index.md)","id":"CVE-2020-26959","markdown":"https://insights.sbomify.com/CVE-2020-26959/index.md","name":"CVE-2020-26959","record":{"aliases":["DEBIAN-CVE-2020-26959","GHSA-w4gq-6hmw-x862","UBUNTU-CVE-2020-26959"],"analysis":{"component_type":"browser","fix_type":"upgrade","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Mozilla Firefox","requires_auth":"none","summary":"A use-after-free vulnerability in Firefox and Thunderbird during shutdown allows attackers to cause memory corruption and potentially execute arbitrary code.","user_interaction":"required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mozilla","cpe":[{"product":"firefox","vendor":"mozilla"},{"product":"firefox_esr","vendor":"mozilla"},{"product":"thunderbird","vendor":"mozilla"}],"cvss":{"score":8.8,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-416","name":"Use After Free"}],"description":"During browser shutdown, reference decrementing could have occured on a previously freed object, resulting in a use-after-free, memory corruption, and a potentially exploitable crash. This vulnerability affects Firefox \u003c 83, Firefox ESR \u003c 78.5, and Thunderbird \u003c 78.5.","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":"Use after free in Firefox","id":"CVE-2020-26959","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"mozilla:firefox","products":["mozilla:firefox","mozilla:firefox_esr","mozilla:thunderbird"],"type":"use_after_free","year":"2020"},"n_packages":0,"n_references":4,"next":{"headline":"Use after free in Firefox","id":"CVE-2020-26960"},"packages":[],"prev":{"headline":"Cross-site scripting in Firefox","id":"CVE-2020-26958"},"products":["Firefox","Firefox ESR","Thunderbird"],"published":"2020-12-09","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":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2024-08-04","vendors":["Mozilla"]},"summary":"A use-after-free vulnerability in Firefox and Thunderbird during shutdown allows attackers to cause memory corruption and potentially execute arbitrary code.","url":"https://insights.sbomify.com/CVE-2020-26959/"}