ID :ISA-2026-049
High alertActiveCVSS 8.8/10IservicesCSIRT

Use-After-Free vulnerability affecting OpenSSL

Executive Summary

A vulnerability affecting OpenSSL would allow an unauthenticated malicious actor to cause an application crash, heap corruption, or, under specific conditions, remote arbitrary code execution on affected systems.

Published on June 12, 2026 at 01:00 AM by Iservices Csirt12 views

Description

Technical context and vulnerability details

OpenSSL is a widely deployed open source cryptographic library, providing implementations of the TLS/SSL protocols as well as cryptographic primitives used in a large number of applications, web servers and network equipment. This library is affected by a vulnerability labeled CVE-2026-45447, resulting from incorrect memory management when verifying digital signatures in PKCS#7 or S/MIME messages. Exploitation of this vulnerability would allow an unauthenticated malicious actor to submit, via any network channel carrying PKCS#7 or S/MIME content, a specially crafted message that could lead to a process crash, heap corruption, or, depending on the behavior of the memory allocator and how the application uses memory, remote arbitrary code execution. It is classified high with a severity score of 8.8 according to CVSS V3.1.

Potential Risks & Impact

Potential consequences upon exploitation

  • Remote Arbitrary Code Execution;
  • Denial of Service (DoS);
  • Data privacy breach;
  • System integrity breach;

Affected systems

Products, components and targeted versions

  • OpenSSL version 4.0.0;
  • OpenSSL versions 3.6.x prior to 3.6.3;
  • OpenSSL versions 3.5.x prior to 3.5.7;
  • OpenSSL versions 3.4.x prior to 3.4.6;
  • OpenSSL versions 3.0.x prior to 3.0.21;
  • OpenSSL versions 1.1.1 prior to 1.1.1zh;
  • OpenSSL versions 1.0.2 prior to 1.0.2zq;

Recommended Remediations & Actions

Immediate actions and recommended mitigations

  • Update OpenSSL to its latest stable version depending on active deployment branch;

Advisory Specifications

ISA-2026-049
CVSS scoreHIGH
8.8/ 10.0
0.0 (Low)5.0 (Med)10.0 (Crit)
PriorityHigh
StatusActive
Typesecurite
Published onJune 12, 2026 at 01:00 AM
OrigineIservicesCSIRT
Audience12 views

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