Is there a public exploit for CVE-2026-11404?

No public exploit for CVE-2026-11404 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-11404?

CVE-2026-11404 scores CVSS 8.7 (v4.0), rated high. EPSS puts the chance of exploitation in the next 30 days at 0.61%.

What does CVE-2026-11404 affect?

CVE-2026-11404 affects Cesanta Mongoose.

8.7 High

Cesanta Mongoose before 7.22 contains an out-of-bounds read in the built-in TLS server function mgtlsserverrecvhello(), which uses an…

CVE-2026-11404

Cesanta Mongoose before 7.22 contains an out-of-bounds read in the built-in TLS server function mgtlsserverrecvhello(), which uses an attacker-controlled sessionidlen byte from a TLS ClientHello as a buffer index without validating it against the length of received data. A remote, unauthenticated attacker can send a single crafted ClientHello with an oversized session id length to read past the receive buffer, crashing any HTTPS, MQTTS, or WSS service built on MGTLSBUILTIN.

Assessment

CVSS: 8.7 (v4.0)
Severity: High
EPSS: 0.61% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 9 July 2026
Last updated: 3 November 2026
Affected: Cesanta · Mongoose
Assigner: VulnCheck

CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

At the source

EUVD (ENISA)

References

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