Denial of Service in uap-core
Description
uap-core in an open-source npm package which contains the core of BrowserScope's original user agent string parser. In uap-core before version 0.11.0, some regexes are vulnerable to regular expression denial of service (REDoS) due to overlapping capture groups. This allows remote attackers to overload a server by setting the User-Agent header in an HTTP(S) request to maliciously crafted long strings. This is fixed in version 0.11.0. Downstream packages such as uap-python, uap-ruby etc which depend upon uap-core follow different version schemes.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
uap-corenpm | < 0.11.0 | 0.11.0 |
Affected products
2Patches
Vulnerability mechanics
Generated on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
5- github.com/advisories/GHSA-p4pj-mg4r-x6v4ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2021-21317ghsaADVISORY
- github.com/ua-parser/uap-core/commit/dc9925d458214cfe87b93e35346980612f6ae96cghsax_refsource_MISCWEB
- github.com/ua-parser/uap-core/security/advisories/GHSA-p4pj-mg4r-x6v4ghsax_refsource_CONFIRMWEB
- www.npmjs.com/package/uap-coreghsax_refsource_MISCWEB
News mentions
0No linked articles in our index yet.