Out-of-bounds Read in Sbabic Swupdate
CVE-2026-28525
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (43.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 43.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Sbabic Swupdate — versions 0, beee2dc0feef1cfe84f1aa6fc980e104b2e47a74
- Swupdate
Weakness classification (CWE)
References
- github.com/sbabic/swupdate/commit/beee2dc0feef1cfe84f1aa6fc980e104b2e47a74 (Patch, patch)
- www.vulncheck.com/advisories/swupdate-integer-underflow-in-multipart-upload-par… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-28525?
- CVE-2026-28525 is a medium-severity vulnerability in Sbabic Swupdate, classified under Out-of-bounds Read. CVSS score: 6.8/10. Published 2026-04-23.
- How severe is CVE-2026-28525?
- Medium severity. CVSS v3 base score is 6.8 out of 10.