Bug 2515196 (CVE-2026-19484) - CVE-2026-19484 fastify/busboy: fastify/busboy: Denial of Service via oversized multipart boundary
Summary: CVE-2026-19484 fastify/busboy: fastify/busboy: Denial of Service via oversize...
Keywords:
Status: NEW
Alias: CVE-2026-19484
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-13 09:21 UTC by OSIDB Bzimport
Modified: 2026-08-18 06:24 UTC (History)
14 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-08-13 09:21:13 UTC
@fastify/busboy is a multipart form-data parser. In versions 3.1.0 through 3.2.0, a remote unauthenticated attacker can stall the Node.js event loop by sending a multipart request whose boundary is crafted to a specific length. The vendored streaming search stores its skip table in a fixed 256 entry byte array, and a boundary of exactly 252 bytes makes the search needle 256 bytes, which truncates the default skip distance to zero and turns the search into a CPU bound loop on a small body. A single small request can keep one core busy and deny service to other requests handled by the same process. The issue is fixed in @fastify/busboy 3.2.1, which widens the skip table so the skip distance is preserved. Users should upgrade to 3.2.1.


Note You need to log in before you can comment on or make changes to this bug.