{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-3909 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2025-3909 is a high-severity cross-site scripting vulnerability in Mozilla Thunderbird, published on 14 May 2025. 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-2025-3909 and fix it if it is affected.\n\nWhat it is: CVE-2025-3909 is a high-severity cross-site scripting vulnerability in Mozilla Thunderbird, published on 14 May 2025. 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-2025-3909 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-2025-3909/ (Markdown: https://insights.sbomify.com/CVE-2025-3909/index.md)","id":"CVE-2025-3909","markdown":"https://insights.sbomify.com/CVE-2025-3909/index.md","name":"CVE-2025-3909","record":{"aliases":["DEBIAN-CVE-2025-3909","GHSA-h6cg-6m9j-xj9g","UBUNTU-CVE-2025-3909"],"analysis":{"component_type":"desktop_application","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Thunderbird email client","requires_auth":"none","summary":"Attackers can execute JavaScript in the file:/// context by spoofing PDF attachments, potentially compromising user systems.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mozilla","cpe":[{"product":"thunderbird","vendor":"mozilla"}],"cvss":{"score":8.1,"severity":"high","source":"cisa-adp","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-356","name":"Missing User Interaction for Potentially Unsafe Action"}],"description":"Thunderbird's handling of the X-Mozilla-External-Attachment-URL header can be exploited to execute JavaScript in the file:/// context. By crafting a nested email attachment (message/rfc822) and setting its content type to application/pdf, Thunderbird may incorrectly render it as HTML when opened, allowing the embedded JavaScript to run without requiring a file download. This behavior relies on Thunderbird auto-saving the attachment to /tmp and linking to it via the file:/// protocol, potentially enabling JavaScript execution as part of the HTML. This vulnerability was fixed in Thunderbird 128.10.1 and Thunderbird 138.0.1.","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":"JavaScript Execution via Spoofed PDF Attachment and file:/// Link","id":"CVE-2025-3909","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"mozilla:thunderbird","products":["mozilla:thunderbird"],"type":"xss","year":"2025"},"n_packages":0,"n_references":3,"next":{"headline":"Org.keycloak.authentication: two factor authentication bypass","id":"CVE-2025-3910"},"packages":[],"prev":{"headline":"Path traversal in OpenVPN 3 Linux","id":"CVE-2025-3908"},"products":["Thunderbird"],"published":"2025-05-14","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":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-04-13","vendors":["Mozilla"]},"summary":"Attackers can execute JavaScript in the file:/// context by spoofing PDF attachments, potentially compromising user systems.","url":"https://insights.sbomify.com/CVE-2025-3909/"}