CVE-2026-13757

Description

A flaw was found in p11-kit. The RPC message attribute parsing functions p11_rpc_message_get_attribute() and p11_rpc_message_get_attribute_array_value() form a mutually-recursive call chain with no recursion depth limit when processing nested CKA_WRAP_TEMPLATE, CKA_UNWRAP_TEMPLATE, and CKA_DERIVE_TEMPLATE attributes. An unauthenticated attacker with local access to the p11-kit RPC Unix domain socket can send a specially crafted request with deeply nested template attributes, causing stack exhaustion and crashing the p11-kit server process and its dependent services.

Mitigation

This CVE requires same-user access to the p11-kit RPC Unix domain socket (/run/user/<uid>/p11-kit/pkcs11-*). Any process running as the socket-owning user can trigger the crash without further authentication.

If p11-kit is managed via systemd --user, ensure `Restart=on-failure` is set in the unit file so that a crash is automatically recovered without manual intervention.

Red Hat recommends updating p11-kit to version 0.26.3 or later, which introduces a recursion depth limit in the RPC attribute parsing and fully addresses this flaw.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score6.2N/A6.2
Attack VectorLocalN/ALocal
Attack ComplexityLowN/ALow
Privileges RequiredNoneN/ANone
User InteractionNoneN/ANone
ScopeUnchangedN/AUnchanged
ConfidentialityNoneN/ANone
Integrity ImpactNoneN/ANone
Availability ImpactHighN/AHigh

Vector

Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Red Hat CVSS v3 Score Explanation

Local attack via Unix domain socket with no authentication. Scope is changed because crashing p11-kit impacts dependent services (SSH agents, VPN clients, browsers).

Understanding the Weakness (CWE)

Availability

Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)

Resources including CPU, memory, and stack memory could be rapidly consumed or exhausted, eventually leading to an exit or crash.

Confidentiality

Technical Impact: Read Application Data

In some cases, an application's interpreter might kill a process or thread that appears to be consuming too much resources, such as with PHP's memory_limit setting. When the interpreter kills the process/thread, it might report an error containing detailed information such as the application's installation path.

Frequently Asked Questions

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