Out-of-bounds read in OpenSSL - CVE-2026-84782
Published: September 30, 2026
Vulnerability identifier: #VU152944
CSH Severity: Medium
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-84782
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose heap memory contents or cause a denial of service.
The vulnerability exists due to an out-of-bounds read in OpenSSL DTLS retransmission handling when retransmitting a suspended DTLS handshake message write. A remote attacker can cause a suspended handshake message to be retransmitted to disclose heap memory contents or cause a denial of service.
Only applications that use DTLS are affected.
Affected software
OpenSSL
Debian Linux
FreeBSD
openssl (Debian package)
Debian Linux
FreeBSD
openssl (Debian package)
How to mitigate CVE-2026-84782
Install security update from vendor's website.
OpenSSL - addressed in versions 1.0.2zs, 1.1.1zj, 3.0.23, 3.4.8, 3.5.9, 3.6.5, 4.0.3
openssl (Debian package) - update to 3.5.7-1~deb13u3
openssl (Debian package) - update to 3.5.7-1~deb13u3