CVE-2026-73252
CVE-2026-73252 · 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
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 7.5 · High · EPSS 0.4% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
mongoose
- Versions
- < 7.23: Affected
No fix published
mongoose Debian:14
- Versions
- 7.21+ds-1
- 7.21+ds-1~bpo13+1
- 7.21+ds-2
- 7.22+ds-1
- 7.22+ds-1~bpo13+1
- 7.23+ds-1~bpo13+1
- Affected ranges
- ECOSYSTEM: < 7.23+ds-1
Update to 7.23+ds-1
mongoose Ubuntu:26.10
- Versions
- 7.21+ds-1
- 7.21+ds-2
- 7.22+ds-1
- 7.23+ds-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published