Summary
Flawfinder output manipulation via untrusted filenames and source text
Workarounds
There is no configuration-based workaround within older versions of flawfinder. If an immediate upgrade is not possible, users can mitigate the risk by:
Pre-scanning filenames: Manually or programmatically verifying that target repositories do not contain filenames with control characters (including ANSI escape sequences) before passing them to flawfinder.
Inspecting raw output: Reviewing flawfinder outputs in a text editor or logging mechanism that explicitly displays or strips raw escape sequences, rather than relying on live terminal rendering.
Restricting untrusted inputs: Avoiding the generation of SonarQube or CSV reports from completely untrusted repositories until the tool is updated.
Resources
See the flawfinder GitHub Repository: https://github.com/david-a-wheeler/flawfinder
Impact
This vulnerability is an improper input neutralization issue leading to output manipulation, specifically, Terminal/ANSI Escape Sequence Injection and XML Injection:
Terminal Output Spoofing: A malicious file whose name contains ANSI escape sequences can end up being included in flawfinder's standard terminal output, with many effects. For example, this might allow an attacker to hide critical scan results, falsely making it appear to a human reviewer that no security issues were found.
CSV and XML Injection: Untrusted fields (such as filenames, categories, or code context text) were not properly sanitized when generating structured reports. An attacker could exploit this to corrupt CSV formats or inject arbitrary XML attributes into SonarQube outputs via output_sonar().
It impacts those who use flawfinder to evaluate intentionally malicious filenames or file contents.
The initial filename injection problem was reported by Dan Lenz https://www.linkedin.com/in/dan-lenz/
The other vulnerabilities were found by flawfinder project leader David A. Wheeler, GitHub david-a-wheeler, https://dwheeler.com/
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
This issue has been fully patched in Version 2.0.20 (released 2026-05-16). All users should upgrade to version 2.0.20 or later immediately. If you use Python's package manager, you can upgrade using pip install --upgrade flawfinder. If you are consuming flawfinder via GitHub Actions, ensure your workflow points to david-a-wheeler/[email protected] or later.
Frequently Asked Questions
- What is CVE-2026-48813? CVE-2026-48813 is a low-severity security vulnerability in flawfinder (pip), affecting versions < 2.0.20. It is fixed in 2.0.20.
- Which versions of flawfinder are affected by CVE-2026-48813? flawfinder (pip) versions < 2.0.20 is affected.
- Is there a fix for CVE-2026-48813? Yes. CVE-2026-48813 is fixed in 2.0.20. Upgrade to this version or later.
- Is CVE-2026-48813 exploitable, and should I be worried? Whether CVE-2026-48813 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-48813 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-48813? Upgrade
flawfinderto 2.0.20 or later.