CVE-2026-73260 (GCVE-0-2026-73260)

Vulnerability from cvelistv5 – Published: 2026-10-14 18:25 – Updated: 2026-10-20 01:50
VLAI
Title
Mongoose: Out-of-bounds Read via length-counter underflow in built-in TLS X.509 DER parser
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TLS certificate parser selected by MG_TLS_BUILTIN fails to verify that a long-form DER element length fits within the remaining certificate buffer. In mg_der_to_tlv() and mg_der_next(), a peer-controlled length can advance the parser beyond the certificate and underflow the remaining uint32_t length, causing mg_tls_parse_cert_der() to continue walking an invalid pointer. An unauthenticated malicious TLS server, or a client presenting a certificate to a server configured for client certificates, can trigger an out-of-bounds read and denial of service during the handshake. This issue is fixed in version 7.23.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-20 01:49 UTC
CWE
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7660 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
cesanta mongoose Affected: < 7.23
guessed Create a notification for this product.
Show details on NVD website
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