Improper Input Validation Affecting mongoose package, versions <7.23+ds-1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIANUNSTABLE-MONGOOSE-18778402
- published14 Aug 2026
- disclosed14 Oct 2026
Introduced: 14 Aug 2026
CVE-2026-73261 (opens in a new tab)How to fix?
Upgrade Debian:unstable mongoose to version 7.23+ds-1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream mongoose package and not the mongoose package as distributed by Debian.
See How to fix? for Debian:unstable relevant fixed versions and status.
Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TCP/IP stack enabled by MG_ENABLE_TCPIP in src/net_builtin.c does not reject a TCP option whose declared opts[1] length exceeds the remaining option bytes. In handle_opt(), a NOP followed by a truncated MSS option causes opts[3] to be read outside the declared options area and used as the low byte of dmss. An unauthenticated remote peer can corrupt the per-connection MSS value so later mg_send() calls transmit truncated or zero-length application payloads while the TCP connection otherwise appears healthy. This issue is fixed in version 7.23.