EUVD-2026-18184
GHSA-hm7q-jq63-pr78
Severity by source
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
6DescriptionCVE.org
A vulnerability was determined in Cesanta Mongoose up to 7.20. Affected is the function mg_tls_verify_cert_signature of the file mongoose.c of the component P-384 Public Key Handler. Executing a manipulation can lead to authorization bypass. The attack can be executed remotely. Attacks of this nature are highly complex. The exploitability is told to be difficult. The exploit has been publicly disclosed and may be utilized. Upgrading to version 7.21 is able to address this issue. This patch is called 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
AnalysisAI
Authorization bypass in Cesanta Mongoose up to version 7.20 allows remote, unauthenticated attackers to bypass TLS certificate signature verification in the P-384 public key handler (mg_tls_verify_cert_signature function in mongoose.c), potentially enabling man-in-the-middle attacks or unauthorized access. The attack is highly complex (CVSS AC:H) but publicly disclosed exploit code exists, with vendor-released patch available in version 7.21.
Technical ContextAI
This vulnerability affects the P-384 elliptic curve cryptography implementation within Mongoose's TLS certificate verification logic, specifically the mg_tls_verify_cert_signature function. P-384 (also known as secp384r1) is a cryptographic algorithm used in digital signature verification during TLS handshakes. The vulnerability (classified as CWE-639: Authorization Bypass Through User-Controlled Key) allows manipulation of the signature verification process, enabling attackers to forge or bypass legitimate certificate validation. This flaw directly impacts the integrity of the TLS stack in Mongoose, a lightweight embedded web server commonly used in IoT devices, firmware, and embedded systems. The CPE cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:* indicates all versions up to 7.20 are affected.
RemediationAI
Vendor-released patch: Upgrade to Cesanta Mongoose version 7.21 or later, which includes the fix commit 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1. This patch directly addresses the P-384 public key signature verification flaw. Installation instructions and release details are available at https://github.com/cesanta/mongoose/releases/tag/7.21. For systems unable to upgrade immediately, restrict TLS connections to trusted certificate authorities or implement certificate pinning to mitigate man-in-the-middle attack risks. No workarounds are available short of upgrade; certificate validation bypass cannot be safely mitigated at the application layer if the underlying TLS library is compromised.
Mongoose ODM for Node.js before version 8.9.5 contains a search injection vulnerability when using $where filters with p
An exploitable stack buffer overflow vulnerability exists in the MQTT packet parsing functionality of Cesanta Mongoose 6
An exploitable use-after-free vulnerability exists in the HTTP server implementation of Cesanta Mongoose 6.8. Rated crit
An exploitable memory corruption vulnerability exists in the Websocket protocol implementation of Cesanta Mongoose 6.8.
An exploitable memory corruption vulnerability exists in the Websocket protocol implementation of Cesanta Mongoose 6.8.
Prototype Pollution in GitHub repository automattic/mongoose prior to 7.3.4. Rated critical severity (CVSS 9.8), this vu
Prototype Pollution in GitHub repository automattic/mongoose prior to 6.4.6. Rated critical severity (CVSS 9.8), this vu
An integer overflow in parse_mqtt in mongoose.c in Cesanta Mongoose 6.16 allows an attacker to achieve remote DoS (infin
Mongoose before 8.8.3 can improperly use $where in match, leading to search injection. Rated critical severity (CVSS 9.1
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 (compiled with OpenSSL support) is vulnerable to remote OO
The mg_tls_init function in Cesanta Mongoose HTTPS server 7.0 and 6.7-6.18 (compiled with mbedTLS support) is vulnerable
The mg_http_serve_file function in Cesanta Mongoose HTTP server 7.0 is vulnerable to remote OOB write attack via connect
Same technique Authentication Bypass
View allShare
External POC / Exploit Code
Leaving vuln.today