CVE-2026-73253
Mongoose: TLS Hostname Verification Bypass via Overly Permissive Wildcard Matching
No known exploitation. EPSS puts it in the 26th percentile. No fix published yet.
What to do
No fixed build or workaround is published yet. Limit exposure and watch for a patch.
What it is
From the CVE record
Mongoose is an embedded web server and network library. Prior to version 7.22, an on-path network attacker with a wildcard certificate for a parent domain can impersonate deeper subdomains to a client using the built-in TLS stack. The mg_tls_verify_cert_san() and mg_tls_verify_cert_cn() functions in src/tls_builtin.c call mg_match(), whose wildcard can cross DNS label boundaries, so a pattern such as *.example.com can match foo.bar.example.com. The resulting hostname verification bypass permits interception and modification of TLS traffic. This issue is fixed in version 7.22.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.4% chance of exploitation activity in the next 30 days, which ranks it in the 26th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
6 events over 20 days, from the signal feeds we watch.
- Record updated
- OpenVAS check added
- Publishedweakness classified, att&ck mapped, record updated
Affected products
Technical detail
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
References in the record
- github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71
- github.com/cesanta/mongoose/pull/3611
- github.com/cesanta/mongoose/releases/tag/7.22
And 1 more reference. See all after sign-in
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