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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| jorisvink | kore | < 4.3.0 | 4.3.0 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | kore | No fix yet | — |
| Debian 12 | kore | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | kore | No fix yet | — |
| Ubuntu 26.04 LTS | kore | No fix yet | — |
| Ubuntu 24.04 LTS | kore | No fix yet | — |
| Ubuntu 22.04 LTS | kore | No fix yet | — |
| Ubuntu 20.04 LTS | kore | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | kore | No fix yet | — |
References
- Patch Commit patch
- https://github.com/jorisvink/kore product
- Kore 4.3.0 Release Notes release-notes
- https://github.com/jorisvink/kore/blob/4.3.0-rc5/src/http.c#L934 technical-description
- VulnCheck Advisory: Kore before 4.3.0 Integer Underflow Memory Exhaustion via http_header_recv() third-party-advisory