CVE-2026-56362
Description
A heap-buffer-overflow read in ImageMagick's OpenPixelCache occurs when image channel metadata updates before memory allocation. Attackers can trigger this via memory and disk allocation failures to disclose sensitive information.
Statement
This vulnerability in ImageMagick is rated as Low impact. A heap-buffer-overflow read can occur in the GetPixelIndex function if OpenPixelCache updates image channel metadata before memory allocation, and both memory and disk allocation subsequently fail. Exploitation requires an attacker to trigger these specific resource exhaustion conditions, which limits the practical attack surface and reduces the overall risk of information disclosure on standard Red Hat deployments.
Mitigation
Isolate ImageMagick tasks by running them inside unprivileged containers (such as Podman) with strict SELinux confinement. Alternatively, sanitize untrusted files using an intermediate script to strip complex metadata before passing them to ImageMagick.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.3 | 4.2 | 3.3 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | High | High |
| Privileges Required | High | Low | High |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | Low | Low |
| Integrity Impact | None | None | None |
| Availability Impact | Low | Low | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:L
NVD: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:L
Red Hat CVSS v3 Score Explanation
The NVD score is high. I have added the statement to explain the practical challenge in exploiting this flaw.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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