CVE-2026-8159
HIGH7.5EPSS 0.06%multiparty vulnerable to ReDoS via filename parsing
Description
### Impact [email protected] and lower versions are vulnerable to denial of service via regular expression backtracking in the `Content-Disposition` filename parameter parser. A multipart upload with a long header value containing `!filename="1` repeated can cause regex matching to take seconds, blocking the event loop. Any service accepting multipart uploads via multiparty is affected. ### Patches Users should upgrade to [email protected] or higher. ### Workarounds None. Limiting upload sizes at the proxy/gateway layer reduces but does not eliminate the attack surface, since a small ~8 KB header is sufficient to trigger the vulnerable backtracking. ### Resources - [OWASP: Regular expression Denial of Service (ReDoS)](https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS)
Affected packages (2)
- Debian/node-multipartyfrom 0
- npm/multipartyfrom 0, < 4.3.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References (7)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-8159
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-8159
- PATCHhttps://github.com/pillarjs/multiparty
- WEBhttps://cna.openjsf.org/security-advisories.html
- WEBhttps://github.com/pillarjs/multiparty/releases/tag/v4.3.0
- WEBhttps://github.com/pillarjs/multiparty/security/advisories/GHSA-65x3-rw7q-gx94
- WEBhttps://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS