CVE-2026-56389
CVE-2026-56389: 1 tracked advisory record across Red Hat. Compare vendor sources and published fix guidance.
Compare the source-linked records below. Ratings and product/version details belong to each advisory; they are not a single CVE-wide score or proof that every listed product is affected. How VulniPulse collects and checks evidence.
Vendor advisory comparison
Red Hat
1 advisory- Advisory severityMedium5.5
Medium [CVE-2026-56389] Arbitrary Code Execution via malicious grammar file
CVE-2026-56389Source published Source updated
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(). When running bison --html on a attacker-provided grammar, this behavior allows execution of an arbitrary program with the privileges of the Bison process. Maintainers 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…
- Affected products in this advisory
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
3 more entries in the full advisory.
- Source-reported affected versions
- 3.8.2
- Source-reported fixed versions
- No fixed-version detail extracted. This does not mean no fix exists.
- Mitigation guidance
- To mitigate this vulnerability, avoid processing untrusted or unverified grammar files with the `bison --html` command. Restrict the use of `bison --html` to trusted input sources only. This operational control reduces the risk of arbitrary code execution by preventing the vulnerable code path from being triggered with malicious input.
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