CVE-2026-5244: Heap-based Buffer Overflow in Cesanta Mongoose
CVE-2026-5244 is a heap-based buffer overflow vulnerability in Cesanta Mongoose versions up to 7. 20, specifically in the mg_tls_recv_cert function of the TLS 1. 3 Handler component. The vulnerability arises from improper handling of the pubkey argument, which can be manipulated remotely to trigger the overflow. A public exploit has been disclosed. The vendor has released version 7. 21 to address this issue.
AI Analysis
Technical Summary
This vulnerability affects the Cesanta Mongoose library up to version 7.20 in the TLS 1.3 Handler's mg_tls_recv_cert function. Manipulation of the pubkey argument leads to a heap-based buffer overflow, which can be exploited remotely without authentication or user interaction. The vendor responded promptly and released a fixed version 7.21, which mitigates the issue. The patch is identified by commit 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1.
Potential Impact
Successful exploitation of this vulnerability could lead to memory corruption due to heap-based buffer overflow, potentially allowing an attacker to cause a denial of service or execute arbitrary code remotely. The CVSS 4.0 base score is 6.9, indicating a medium severity impact with network attack vector, low complexity, no privileges or user interaction required, and limited confidentiality, integrity, and availability impacts.
Mitigation Recommendations
A fixed version 7.21 of Cesanta Mongoose has been released by the vendor to address this vulnerability. It is strongly recommended to upgrade to version 7.21 or later. Since this is not a cloud service, remediation depends on applying the vendor's patch. Patch status is confirmed by the vendor's official release and the provided patch commit.
CVE-2026-5244: Heap-based Buffer Overflow in Cesanta Mongoose
Description
CVE-2026-5244 is a heap-based buffer overflow vulnerability in Cesanta Mongoose versions up to 7. 20, specifically in the mg_tls_recv_cert function of the TLS 1. 3 Handler component. The vulnerability arises from improper handling of the pubkey argument, which can be manipulated remotely to trigger the overflow. A public exploit has been disclosed. The vendor has released version 7. 21 to address this issue.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability affects the Cesanta Mongoose library up to version 7.20 in the TLS 1.3 Handler's mg_tls_recv_cert function. Manipulation of the pubkey argument leads to a heap-based buffer overflow, which can be exploited remotely without authentication or user interaction. The vendor responded promptly and released a fixed version 7.21, which mitigates the issue. The patch is identified by commit 0d882f1b43ff2308b7486a56a9d60cd6dba8a3f1.
Potential Impact
Successful exploitation of this vulnerability could lead to memory corruption due to heap-based buffer overflow, potentially allowing an attacker to cause a denial of service or execute arbitrary code remotely. The CVSS 4.0 base score is 6.9, indicating a medium severity impact with network attack vector, low complexity, no privileges or user interaction required, and limited confidentiality, integrity, and availability impacts.
Mitigation Recommendations
A fixed version 7.21 of Cesanta Mongoose has been released by the vendor to address this vulnerability. It is strongly recommended to upgrade to version 7.21 or later. Since this is not a cloud service, remediation depends on applying the vendor's patch. Patch status is confirmed by the vendor's official release and the provided patch commit.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulDB
- Date Reserved
- 2026-03-31T14:45:47.381Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 69ce74d2e6bfc5ba1ddd16d8
Added to database: 4/2/2026, 1:53:22 PM
Last enriched: 4/10/2026, 12:13:57 AM
Last updated: 5/20/2026, 8:50:38 PM
Views: 80
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