Bug 2552780 (CVE-2026-73252)

Summary: CVE-2026-73252 mongoose: Mongoose: Denial of Service via crafted TLS record
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Mongoose. An unauthenticated remote attacker can cause a Denial of Service (DoS) by sending a specially crafted Transport Layer Security (TLS) record to an affected server. Due to improper message length validation in the built-in TLS implementation, processing the malformed record triggers an integer underflow and an out-of-bounds memory read, causing the application to crash.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2553622    
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Description OSIDB Bzimport 2026-10-14 18:41:56 UTC 
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.