CVE-2026-42046: libcaca Integer Overflow Resurfaces, RCE Risk
The National Vulnerability Database has detailed CVE-2026-42046, a critical integer overflow vulnerability in libcaca, a library for colour ASCII art. This flaw, present in versions 0.99.beta20 and earlier, allows an attacker to trigger a controlled heap out-of-bounds write (heap overflow) by providing a specially crafted file in the “caca” format. This isn’t new territory; it’s the same underlying issue as CVE-2021-3410, indicating the prior fix was incomplete.
Successful exploitation carries severe consequences. Depending on the specific build configuration and memory allocator, this heap overflow can lead directly to memory corruption or, more alarmingly, remote code execution (RCE). The National Vulnerability Database assigns a CVSS v3.1 score of 7.8 (HIGH), reflecting the high impact on confidentiality, integrity, and availability, coupled with low attack complexity and no required privileges, though user interaction is necessary.
While specific affected products aren’t listed, any application or system incorporating vulnerable versions of libcaca is at risk. Defenders must recognize that this type of heap overflow, particularly one leading to RCE, is a prime target for attackers looking to gain deep system access. The fix is identified as commit fb77acff9ba6bb01d53940da34fb10f20b156a23.
What This Means For You
- If your organization utilizes libcaca, directly or indirectly through other software, you need to identify vulnerable versions immediately. This isn't just a crash; it's a potential RCE. Audit your software dependencies for libcaca and ensure you're on a patched version beyond 0.99.beta20 that incorporates commit `fb77acff9ba6bb01d53940da34fb10f20b156a23`. This is a classic supply chain risk – don't assume your vendor has everything patched.
Related ATT&CK Techniques
🛡️ Detection Rules
3 rules · 6 SIEM formats3 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
CVE-2026-42046: libcaca Canvas Import Heap Overflow Attempt
title: CVE-2026-42046: libcaca Canvas Import Heap Overflow Attempt
id: scw-2026-05-11-ai-1
status: experimental
level: high
description: |
Detects potential exploitation of CVE-2026-42046 by looking for processes attempting to use the 'caca_import_canvas' function, which is vulnerable to an integer overflow leading to a heap out-of-bounds write. This is a direct indicator of an attempt to trigger the vulnerability in libcaca versions prior to the fix.
author: SCW Feed Engine (AI-generated)
date: 2026-05-11
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-42046/
tags:
- attack.execution
- attack.t1204.002
logsource:
category: process_creation
detection:
selection:
Image|contains:
- 'libcaca'
CommandLine|contains:
- 'caca_import_canvas'
condition: selection
falsepositives:
- Legitimate administrative activity
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-42046 | RCE | libcaca versions 0.99.beta20 and earlier |
| CVE-2026-42046 | Memory Corruption | libcaca versions 0.99.beta20 and earlier |
| CVE-2026-42046 | Heap Overflow | libcaca canvas import functionality with crafted 'caca' format file |
| CVE-2026-42046 | Integer Overflow | libcaca canvas import functionality |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 12, 2026 at 01:22 UTC |
This content was AI-rewritten and enriched by Shimi's Cyber World based on the original source. All intellectual property rights remain with the original author.
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