# CVE-2026-28525: swupdate: SWUpdate contains an integer underflow vulnerability in the multipart upload parser in mongoose_multipart.c that allo...

CVE-2026-28525 is fixed in swupdate on 1 platform, first by DEBIAN-CVE-2026-28525, released April 23, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-28525
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0032
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 23, 2026

## Description

SWUpdate contains an integer underflow vulnerability in the multipart upload parser in mongoose_multipart.c that allows unauthenticated attackers to cause a denial of service by sending a crafted HTTP POST request to /upload with a malformed multipart boundary and controlled TCP stream timing. Attackers can trigger an integer underflow in the mg_http_multipart_continue_wait_for_chunk() function when the buffer length falls within a specific range, causing an out-of-bounds heap read past the allocated receive buffer to a local IPC socket.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | swupdate Debian 12.15 (bookworm) | 2022.12+dfsg-4+deb12u2 | [DEBIAN-CVE-2026-28525](https://patchblox.com/security/data/fix/linux/debian-cve-2026-28525.md) | Apr 23, 2026 |
| Linux | swupdate Debian 13.5 (trixie) | 2024.12.1+dfsg-3+deb13u2 | [DEBIAN-CVE-2026-28525](https://patchblox.com/security/data/fix/linux/debian-cve-2026-28525.md) | Apr 23, 2026 |
| Linux | swupdate Debian 14 | 2025.12+dfsg-9 | [DEBIAN-CVE-2026-28525](https://patchblox.com/security/data/fix/linux/debian-cve-2026-28525.md) | Apr 23, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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