CVE-2026-73252 (GCVE-0-2026-73252)

Vulnerability from cvelistv5 – Published: 2026-10-14 18:24 – Updated: 2026-10-14 19:41
VLAI
Title
Mongoose: Unauthenticated remote heap out-of-bounds read in built-in TLS: off-by-one length check in mg_tls_recv_record() underflows recv_len to SIZE_MAX
Summary
Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TLS stack selected by MG_TLS_BUILTIN in src/tls_builtin.c accepts a TLS 1.3 record whose decrypted size is exactly the 16-byte authentication tag with no plaintext or ContentType byte. In mg_tls_recv_record(), the msgsz length check permits that record and the recv_len calculation underflows to SIZE_MAX, so a later handshake step treats stale buffer contents as a trusted message with an effectively unbounded length. An unauthenticated malicious TLS peer can trigger a heap out-of-bounds read before certificate or Finished validation, causing a remote denial of service. 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 2026-10-14 19:41 UTC
CWE
  • CWE-191 - Integer Underflow (Wrap or Wraparound)
  • CWE-125 - Out-of-bounds Read
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7771 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
To clipboard 

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