CVE-2025-8736
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability, which was classified as critical, has been found in GNU cflow up to 1.8. Affected by this issue is the function yylex of the file c.c of the component Lexer. The manipulation leads to buffer overflow. Local access is required to approach this attack. The exploit has been disclosed to the public and may be used.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA buffer overflow vulnerability exists in GNU cflow up to version 1.8 in the yylex function within the lexer component (c.c). The vulnerability allows local attackers to potentially execute arbitrary code or cause denial of service via crafted input that overflows a buffer in the lexical analyzer.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Verify GNU cflow is installedRun 'cflow --version' or check for the binary at /usr/bin/cflow using 'which cflow'Affected if cflow is present on the system
-
Determine the installed versionExecute 'cflow --version' and note the version number in the output (e.g., cflow 1.8, cflow 1.7, etc.)Affected if the version displayed is 1.8 or earlier
-
Confirm the vulnerability applies to the lexer componentThis vulnerability is in the yylex function within lexer component (c.c), triggered when processing input files via 'cflow [input_file]'Affected if cflow processes any input file using its lexer (the default behavior for parsing C source files)
-
Identify if untrusted or external input files are processedReview usage patterns to determine if cflow is run against files from untrusted sources, shared directories, or user-supplied inputAffected if cflow processes files from untrusted or external sources
The system is affected if GNU cflow version 1.8 or earlier is installed and processes input files through its lexer component, as the buffer overflow occurs when parsing crafted input.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade to a patched version of GNU cflow. If no patched version is available, restrict local access to the application and sanitize input files before processing.
GNU cflow 1.9 (or latest stable release)
- 1. Identify the current installed version of GNU cflow using: cflow --version
- 2. If the installed version is 1.8 or earlier, upgrade to GNU cflow version 1.9 or later
- 3. Download the latest GNU cflow release from the official GNU ftp site: https://ftp.gnu.org/gnu/cflow/
- 4. Extract the source archive and navigate to the directory
- 5. Run ./configure to prepare the build, then make and make install to install the updated version
- 6. Verify the new version is installed: cflow --version
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA6.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,192.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-8736 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-8736 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data