{"answers":{"affected":"It affects 3 products.","exploited":"There is no known exploitation of CVE-2020-26956 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2020-26956 is a medium-severity cross-site scripting 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-2020-26956 and fix it if it is affected.\n\nWhat it is: CVE-2020-26956 is a medium-severity cross-site scripting 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-2020-26956 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-2020-26956/ (Markdown: https://insights.sbomify.com/CVE-2020-26956/index.md)","id":"CVE-2020-26956","markdown":"https://insights.sbomify.com/CVE-2020-26956/index.md","name":"CVE-2020-26956","record":{"aliases":["DEBIAN-CVE-2020-26956","GHSA-2rfm-q54c-ww9j","UBUNTU-CVE-2020-26956"],"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":"Attackers can execute arbitrary scripts via SVG event handlers retained during HTML sanitization in Firefox and Thunderbird.","user_interaction":"required","vuln_class":"xss"},"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":6.1,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. 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":"Cross-site scripting in Firefox","id":"CVE-2020-26956","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"mozilla:firefox","products":["mozilla:firefox","mozilla:firefox_esr","mozilla:thunderbird"],"type":"xss","year":"2020"},"n_packages":0,"n_references":4,"next":{"headline":"Security feature bypass in Firefox","id":"CVE-2020-26957"},"packages":[],"prev":{"headline":"Information disclosure in Firefox","id":"CVE-2020-26955"},"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":"Attackers can execute arbitrary scripts via SVG event handlers retained during HTML sanitization in Firefox and Thunderbird.","url":"https://insights.sbomify.com/CVE-2020-26956/"}