{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-84639 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-84639 is a critical memory corruption vulnerability in Mozilla Thunderbird, published on 1 Sep 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-2026-84639 and fix it if it is affected.\n\nWhat it is: CVE-2026-84639 is a critical memory corruption vulnerability in Mozilla Thunderbird, published on 1 Sep 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-2026-84639 in the wild and no public exploit code.\n\nAffected product: Mozilla Thunderbird. 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-2026-84639/ (Markdown: https://insights.sbomify.com/CVE-2026-84639/index.md)","id":"CVE-2026-84639","markdown":"https://insights.sbomify.com/CVE-2026-84639/index.md","name":"CVE-2026-84639","record":{"aliases":["DEBIAN-CVE-2026-84639","GHSA-4x6j-cpvp-7f2c","UBUNTU-CVE-2026-84639"],"analysis":{"component_type":"desktop_application","fix_type":"upgrade","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Thunderbird email client","requires_auth":"none","summary":"An attacker can exploit uninitialized memory in MIME parsing to potentially execute code or cause a denial of service in Thunderbird.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mozilla","cpe":[{"product":"thunderbird","vendor":"mozilla"}],"cvss":{"score":9.1,"severity":"critical","source":"cisa-adp","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-457","name":"Use of Uninitialized Variable"}],"description":"Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used. This vulnerability was fixed in Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.","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":"Uninitialized memory in MIME parsing","id":"CVE-2026-84639","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"mozilla:thunderbird","products":["mozilla:thunderbird"],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":4,"next":{"headline":"One byte overflow read in mail parser","id":"CVE-2026-84640"},"packages":[],"prev":{"headline":"Calendar invitation attachments could launch local executables","id":"CVE-2026-84637"},"products":["Thunderbird"],"published":"2026-09-01","related":[{"cvss_score":9.8,"headline":"Ambiguous parsing of mail headers","id":"CVE-2026-92238","kev_date_added":null,"published":"2026-09-15"},{"cvss_score":9.8,"headline":"Calendar invitation attachments could launch local executables","id":"CVE-2026-84637","kev_date_added":null,"published":"2026-09-01"},{"cvss_score":9.8,"headline":"Memory corruption in Thunderbird","id":"CVE-2021-43529","kev_date_added":null,"published":"2023-02-16"},{"cvss_score":9.8,"headline":"Memory corruption in Thunderbird","id":"CVE-2019-11703","kev_date_added":null,"published":"2019-07-23"},{"cvss_score":9.8,"headline":"Memory corruption in Thunderbird","id":"CVE-2019-11704","kev_date_added":null,"published":"2019-07-23"},{"cvss_score":9.8,"headline":"Memory corruption in Thunderbird","id":"CVE-2019-11705","kev_date_added":null,"published":"2019-07-23"},{"cvss_score":9.8,"headline":"Use after free in Thunderbird","id":"CVE-2018-18512","kev_date_added":null,"published":"2019-04-26"}],"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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-17","vendors":["Mozilla"]},"summary":"An attacker can exploit uninitialized memory in MIME parsing to potentially execute code or cause a denial of service in Thunderbird.","url":"https://insights.sbomify.com/CVE-2026-84639/"}