CVE-2026-121727
Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that…
- Risk score
- 50/100
- CVSS
- 7.5 v3.1
- Published
- 3 Nov 2026
Open in the live forecast Today's forecast
What to know
- What it is
- Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length t…
- Affected
- See advisory
- Fix
- Upgrade the product to 4.3.0 or later.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 7.5 high
- Remotely exploitable without logging in
References
- https://github.com/jorisvink/kore
- https://github.com/jorisvink/kore/blob/4.3.0-rc5/src/http.c#L934
- https://github.com/jorisvink/kore/commit/1ff3c0f6f7973dc7fc8bf38369790ef2d8079b3b
- https://kore.io/releases/4.3.0
- https://www.vulncheck.com/advisories/kore-before-4.3.0-integer-underflow-memory-exhaustion-via-http-header-recv
Original description
Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.
Last activity 3 Nov 2026. Patch Forecast updates every hour.