CVE-2026-42301: Improper Input Validation leading to Improper Control of Generation of Code ('Code Injection') in pyp2spec

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-09 · updated 2026-07-24
Weakness: CWE-20

Description

pyp2spec generates working Fedora RPM spec file for Python projects. Prior to version 0.14.1, pyp2spec was writing PyPI package metadata (e.g. the summary field) into the generated spec file without escaping RPM macro directives. When a packager then runs rpmbuild, those directives get evaluated, so a malicious package can execute arbitrary commands on the build machine. This issue has been patched in version 0.14.1.

Affected products

befeleme pyp2spec: before 0.14.1

References

https://github.com/befeleme/pyp2spec/releases/tag/v0.14.1
https://github.com/befeleme/pyp2spec/security/advisories/GHSA-r35x-v8p8-xvhw

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