En resumen
- CVE-2026-8159 es una vulnerabilidad ALTO (CVSS 7.5) que afecta a multiparty (pillarjs), multiparty.
- Probabilidad de explotación en los próximos 30 días (EPSS): 0.34%, mayor que el 27.0% de las vulnerabilidades.
- Solución: actualizar a 4.3.0 o posterior.
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
NVD 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.
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