CVE-2026-8159 Details
Description
[email protected] and lower versions are vulnerable to denial of service via regular expression backtracking in the Content-Disposition filename parameter parser. A crafted multipart upload with a long header value can cause regex matching to take seconds, blocking the event loop. Impact: any service accepting multipart uploads via multiparty is affected. Workarounds: limiting upload sizes at the proxy or gateway layer reduces but does not eliminate the attack surface, since a small header of around 8 KB is sufficient to trigger the vulnerable backtracking. Upgrade to [email protected] or higher.
A denial-of-service vulnerability has been identified in the multiparty package, specifically in versions through 4.2.3. The issue arises from regular expression backtracking in the Content-Disposition filename parameter parser. A crafted multipart upload with a long header value can cause the regex matching process to take several seconds, effectively blocking the event loop. This vulnerability affects any service that accepts multipart uploads via multiparty.
Users are advised to upgrade to multiparty version 4.3.0 or higher.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 12, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://cna.openjsf.org/security-advisories.html | openjs | Third Party Advisory |
| https://github.com/pillarjs/multiparty/security/advisories/GHSA-65x3-rw7q-gx94 | openjs | MitigationVendor Advisory |
| https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS | openjs | Not Applicable |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-1333 | Inefficient Regular Expression Complexity | openjs |
Affected Products
| Product | Versions |
|---|---|
| pillarjs multiparty | < 4.3.0 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | openjs |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 13, 2026 | Initial Analysis | [email protected] |
| May 12, 2026 | New CVE Received | openjs |