{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-56390 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-56390 is a medium-severity path traversal vulnerability in GNU Bison, published on 29 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-56390 and fix it if it is affected.\n\nWhat it is: CVE-2026-56390 is a medium-severity path traversal vulnerability in GNU Bison, published on 29 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-56390 in the wild and no public exploit code.\n\nAffected product: GNU Bison. 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-2026-56390/ (Markdown: https://insights.sbomify.com/CVE-2026-56390/index.md)","id":"CVE-2026-56390","markdown":"https://insights.sbomify.com/CVE-2026-56390/index.md","name":"CVE-2026-56390","record":{"aliases":["AZL-94136","DEBIAN-CVE-2026-56390","ECHO-c721-9c49-ec13","GHSA-3pcj-vqw8-47jm","JLSEC-2026-1346","UBUNTU-CVE-2026-56390"],"analysis":{"component_type":"developer_tool","fix_type":"patch","impacts":["data_modify"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"GNU Bison parser generator","requires_auth":"none","summary":"Attackers can overwrite arbitrary files by supplying malicious grammar directives to GNU Bison, potentially compromising system integrity.","user_interaction":"required","vuln_class":"path_traversal"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"CERT-PL","cpe":[{"product":"bison","vendor":"gnu"}],"cvss":{"score":4.6,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-73","name":"External Control of File Name or Path"}],"description":"GNU Bison improperly handles grammar‑defined output paths. Grammar directives such as %output and %header allow specifying file paths, which are accepted without restriction and override caller‑supplied output options. \nWhen processing attacker-supplied grammar, this behavior allows directing generated files to arbitrary writable locations on the filesystem, potentially overwriting existing files accessible to the Bison process.\n\nMaintainers of this project were notified about this vulnerability, and fixed the issue in commit 8d101c19d4d9aaedf83a448c925513742d4efcf0. However, they did not provide vulnerable version range. Version 3.8.2 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.","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":"Arbitrary Output Location Change in GNU Bison","id":"CVE-2026-56390","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"path_traversal","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"Out‑of‑bounds Read in GNU coreutils","id":"CVE-2026-56391"},"packages":[],"prev":{"headline":"Arbitrary Command Execution in GNU Bison","id":"CVE-2026-56389"},"products":["Bison"],"published":"2026-07-29","related":[{"cvss_score":6.8,"headline":"Arbitrary Command Execution in GNU Bison","id":"CVE-2026-56389","kev_date_added":null,"published":"2026-07-29"},{"cvss_score":5.5,"headline":"Use after free in n/a","id":"CVE-2020-24240","kev_date_added":null,"published":"2020-08-25"},{"cvss_score":5.5,"headline":"Denial of service in n/a","id":"CVE-2020-14150","kev_date_added":null,"published":"2020-06-15"}],"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":"partial"},"state":"PUBLISHED","updated":"2026-07-29","vendors":["GNU"]},"summary":"Attackers can overwrite arbitrary files by supplying malicious grammar directives to GNU Bison, potentially compromising system integrity.","url":"https://insights.sbomify.com/CVE-2026-56390/"}