CVE-2026-22795 Overview
CVE-2026-22795 is a type confusion vulnerability in OpenSSL's PKCS#12 parsing code that can lead to a NULL or invalid pointer dereference when an application processes a malformed PKCS#12 file. This vulnerability exists because an ASN1_TYPE union member is accessed without first validating the type, causing an invalid pointer read and resulting in a Denial of Service condition.
Critical Impact
Applications processing untrusted or maliciously crafted PKCS#12 files may crash due to NULL pointer dereference, causing service disruption and potential availability issues.
Affected Products
- OpenSSL 3.6
- OpenSSL 3.5
- OpenSSL 3.4
- OpenSSL 3.3
- OpenSSL 3.0
- OpenSSL 1.1.1
Discovery Timeline
- 2026-01-27 - CVE CVE-2026-22795 published to NVD
- 2026-01-29 - Last updated in NVD database
Technical Details for CVE-2026-22795
Vulnerability Analysis
This vulnerability stems from improper type validation in OpenSSL's PKCS#12 file parsing implementation. When processing PKCS#12 files, the code accesses an ASN1_TYPE union member without first confirming the correct type is being accessed. This type confusion allows an attacker to craft a malicious PKCS#12 file that triggers an invalid pointer read operation.
The exploitability is limited by several factors. The pointer manipulation is constrained to a 1-byte address space, meaning targeted addresses can only fall between 0x00 and 0xFF. This range corresponds to the zero page memory region, which is unmapped on most modern operating systems and will reliably cause a crash rather than enabling code execution.
Additionally, successful exploitation requires a user or application to process the maliciously crafted PKCS#12 file. Since PKCS#12 files are typically used to store private keys and are usually obtained from trusted sources, the attack surface is inherently limited.
It's worth noting that the FIPS modules in versions 3.5, 3.4, 3.3, and 3.0 are not affected by this issue, as the PKCS12 implementation lies outside the OpenSSL FIPS module boundary. OpenSSL 1.0.2 is also not affected by this vulnerability.
Root Cause
The root cause is a type confusion vulnerability (CWE-754: Improper Check for Unusual or Exceptional Conditions) in the PKCS#12 parsing code. The code fails to validate that the correct type is being accessed when dereferencing an ASN1_TYPE union member. Without proper type checking, a malformed input can cause the parser to interpret data incorrectly, leading to an invalid memory access.
Attack Vector
The attack requires local access with user interaction. An attacker must convince a user or application to process a specially crafted PKCS#12 file. The malformed file exploits the type confusion in the ASN.1 parsing logic, causing the application to attempt to read from an invalid memory address (within the 0x00-0xFF range), which triggers a crash.
The vulnerability mechanism involves crafting a PKCS#12 file with incorrect ASN.1 type tags that mislead the parser into accessing memory through an invalid pointer. When the parser encounters this malformed structure, it dereferences the union member assuming a valid type, but instead encounters an unexpected value that results in a pointer to the zero page memory region. For detailed technical analysis, refer to the OpenSSL Security Advisory.
Detection Methods for CVE-2026-22795
Indicators of Compromise
- Application crashes or unexpected termination when processing PKCS#12 files
- Crash dumps showing NULL pointer dereference in OpenSSL PKCS#12 parsing functions
- Unusual or malformed PKCS#12 files appearing in application input directories
Detection Strategies
- Monitor application logs for segmentation faults or access violations during PKCS#12 file processing
- Implement file integrity monitoring for directories where PKCS#12 files are processed
- Deploy SentinelOne Singularity to detect exploitation attempts and abnormal process termination patterns
Monitoring Recommendations
- Enable crash reporting and analysis for applications that process cryptographic files
- Monitor for repeated crashes in SSL/TLS-related services that may indicate exploitation attempts
- Track unusual file processing patterns, particularly for .p12 and .pfx file extensions
How to Mitigate CVE-2026-22795
Immediate Actions Required
- Update OpenSSL to the latest patched version for your release branch
- Audit applications to identify those processing untrusted PKCS#12 files
- Implement input validation to reject malformed PKCS#12 files before processing
- Restrict PKCS#12 file processing to trusted sources only
Patch Information
OpenSSL has released patches addressing this vulnerability. The fixes are available in the following commits:
- GitHub OpenSSL Commit Fix
- GitHub OpenSSL Commit Update
- GitHub OpenSSL Commit Change
- GitHub OpenSSL Commit Improvement
- GitHub OpenSSL Commit Adjustment
For complete details, review the OpenSSL Security Advisory.
Workarounds
- Avoid processing PKCS#12 files from untrusted or unknown sources
- Implement application-level input validation before passing PKCS#12 files to OpenSSL
- Consider using FIPS-validated OpenSSL modules which are unaffected by this vulnerability
# Check current OpenSSL version
openssl version -a
# Verify if your version is affected (versions 1.1.1, 3.0, 3.3, 3.4, 3.5, 3.6 are vulnerable)
# Update OpenSSL to the latest patched version
# For package-managed systems:
# Ubuntu/Debian: sudo apt update && sudo apt upgrade openssl
# RHEL/CentOS: sudo yum update openssl
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
