CVE-2026-18938
Received Received - Intake

Integer Overflow Leading to Heap Out-of-Bounds Write in p11-kit

Publication date: 2026-08-07

Last updated on: 2026-08-07

Assigner: Red Hat, Inc.

Description
A flaw was found in p11-kit. A local attacker, or one with equivalent access to a reachable RPC channel, could exploit an integer overflow vulnerability. By sending specially crafted messages, the attacker can cause the system to miscalculate memory allocation for nested attributes. This leads to a memory corruption issue, specifically a heap out-of-bounds write, which can crash the p11-kit RPC parsing process, resulting in a Denial of Service (DoS). This vulnerability is only exploitable on 32 bit systems.

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Meta Information

Published
2026-08-07
Last Modified
2026-08-07
Generated
2026-08-07
AI Q&A
2026-08-07
EPSS Evaluated
N/A
NVD
CVE-2026-18938
EUVD
EUVD-2026-54413

Affected Vendors & Products

Currently, no data is known.

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
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().

Attack-Flow Graph

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Executive Summary

This is an integer overflow vulnerability in the p11-kit library. It occurs when a local attacker or someone with access to a reachable RPC channel sends specially crafted messages. The system miscalculates memory allocation for nested attributes due to the overflow, leading to a heap out-of-bounds write. This causes memory corruption and crashes the p11-kit RPC parsing process, resulting in a Denial of Service (DoS). The vulnerability only affects 32-bit systems.

Detection Guidance

Detection involves checking if your system runs a vulnerable p11-kit version on a 32-bit ILP32 build. Use commands like 'rpm -q p11-kit' or 'dpkg -l p11-kit' to check installed versions. Verify system architecture with 'uname -m' to confirm 32-bit operation. Monitor for crashes in p11-kit RPC parsing processes.

Impact Analysis

The main impact is a Denial of Service (DoS) where the p11-kit RPC parsing process crashes. This can disrupt services relying on p11-kit, especially on 32-bit systems. Exploitation requires an attacker to send crafted RPC messages, which could be done without user interaction. There is no evidence of confidentiality or integrity compromise.

Compliance Impact

This vulnerability primarily causes a Denial of Service (DoS) by crashing the p11-kit RPC parsing process through memory corruption. It does not directly impact data confidentiality or integrity, which are key concerns for GDPR and HIPAA compliance. However, a DoS condition could disrupt services handling sensitive data, potentially leading to compliance issues if critical systems become unavailable.

Mitigation Strategies

Mitigation options are limited. Avoid exposing the p11-kit RPC parser to untrusted sources. If possible, switch from 32-bit ILP32 builds to 64-bit systems. Monitor for crashes and apply updates if Red Hat releases patches. No official fixes are currently available.

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