{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-56389 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-56389 is a medium-severity command injection 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-2026-56389 and fix it if it is affected.\n\nWhat it is: CVE-2026-56389 is a medium-severity command injection 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-2026-56389 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-2026-56389/ (Markdown: https://insights.sbomify.com/CVE-2026-56389/index.md)","id":"CVE-2026-56389","markdown":"https://insights.sbomify.com/CVE-2026-56389/index.md","name":"CVE-2026-56389","record":{"aliases":["AZL-94133","DEBIAN-CVE-2026-56389","ECHO-5a4d-f9a3-722e","GHSA-735p-4prj-f62v","JLSEC-2026-1345","UBUNTU-CVE-2026-56389","USN-8777-1"],"analysis":{"component_type":"developer_tool","fix_type":"patch","impacts":["code_execution"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"GNU Bison parser generator","requires_auth":"none","summary":"Attackers can execute arbitrary commands by providing a malicious grammar file to GNU Bison during HTML report generation.","user_interaction":"required","vuln_class":"command_injection"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"CERT-PL","cpe":[{"product":"bison","vendor":"gnu"}],"cvss":{"score":6.8,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:L/SC:L/SI:L/SA:L","version":"4.0"},"cwes":[{"id":"CWE-78","name":"Improper Neutralization of Special Elements used in an OS Command"}],"description":"GNU Bison allows for an execution of an arbitrary program during HTML report generation due to improper handling of grammar-defined configuration variables. A grammar file can override the executable used for the XML‑to‑HTML transformation step via %define tool.xsltproc, which is accepted without restriction and passed directly to execvp().\n \nWhen running bison --html on a attacker-provided grammar, this behavior allows execution of an arbitrary program with the privileges of the Bison process.\n\nMaintainers of this project were notified about this vulnerability, and fixed the issue in commit 3169c1e7a2c6acc4c59dfcf8b089896d6881925b. 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 Command Execution in GNU Bison","id":"CVE-2026-56389","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"command_injection","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"Arbitrary Output Location Change in GNU Bison","id":"CVE-2026-56390"},"packages":[],"prev":{"headline":"Apache bRPC: Out-of-Bounds Write in Redis Command Parser","id":"CVE-2026-56388"},"products":["Bison"],"published":"2026-07-29","related":[{"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"},{"cvss_score":4.6,"headline":"Arbitrary Output Location Change in GNU Bison","id":"CVE-2026-56390","kev_date_added":null,"published":"2026-07-29"}],"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 execute arbitrary commands by providing a malicious grammar file to GNU Bison during HTML report generation.","url":"https://insights.sbomify.com/CVE-2026-56389/"}