CVE-2026-5264 | wolfSSL up to 5.9.0 DTLS heap-based overflow

VDB-356795 · CVE-2026-5264 · GCVE-0-2026-5264 WOLFSSL UP TO 5.9.0 DTLS HEAP-BASED OVERFLOW HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 7.0 $0-$5k 2.02+ Summaryinfo A vulnerability was found in wolfSSL up to 5.9.0. It has been classified as critical. Affected is an unknown function of the component DTLS Handler. The manipulation leads to heap-based overflow. This vulnerability is referenced as CVE-2026-5264. Remote exploitation of the attack is possible. No exploit is available. Upgrading the affected component is recommended. Detailsinfo A vulnerability was found in wolfSSL up to 5.9.0. It has been rated as critical. This issue affects an unknown code block of the component DTLS Handler. The manipulation with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Impacted is confidentiality, integrity, and availability. The summary by CVE is: Heap buffer overflow in DTLS 1.3 ACK message processing. A remote attacker can send a crafted DTLS 1.3 ACK message that triggers a heap buffer overflow. The weakness was published by Sunwoo Lee. It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-5264 since 03/31/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. Upgrading to version 5.9.1 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version. Productinfo Name wolfSSL Version 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9.0 License open-source Website Product: https://github.com/wolfssl/wolfssl/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA CVSS-B Score: 🔒 CNA CVSS-BT Score: 🔒 CNA Vector: 🔒 CVSSv3info VulDB Meta Base Score: 7.3 VulDB Meta Temp Score: 7.0 VulDB Base Score: 7.3 VulDB Temp Score: 7.0 VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Heap-based overflow CWE: CWE-122 / CWE-119 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: wolfSSL 5.9.1 Patch: github.com Timelineinfo 03/31/2026 CVE reserved 04/10/2026 +10 days Advisory disclosed 04/10/2026 +0 days VulDB entry created 04/10/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: github.com Researcher: Sunwoo Lee Status: Confirmed CVE: CVE-2026-5264 (🔒) GCVE (CVE): GCVE-0-2026-5264 GCVE (VulDB): GCVE-100-356795 Entryinfo Created: 04/10/2026 06:59 Changes: 04/10/2026 06:59 (68) Complete: 🔍 Cache ID: 99:D43:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸