CVE-2026-33636
Description
A flaw was found in libpng. A remote attacker could exploit an out-of-bounds read and write vulnerability in the ARM/AArch64 Neon-optimized palette expansion path. This occurs when processing a final partial chunk of 8-bit paletted rows without verifying sufficient input pixels, leading to dereferencing pointers before the start of the row buffer and writing expanded pixel data to underflowed positions. This flaw can result in information disclosure and denial of service.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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 Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.6 | N/A | 7.6 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
Understanding the Weakness (CWE)
Integrity,Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart
Out of bounds memory access will very likely result in the corruption of relevant memory, and perhaps instructions, possibly leading to a crash.
Integrity,Confidentiality,Availability,Access Control,Other
Technical Impact: Execute Unauthorized Code or Commands; Modify Memory; Bypass Protection Mechanism; Other
If the corrupted memory can be effectively controlled, it may be possible to execute arbitrary code. If the corrupted memory is data rather than instructions, the system will continue to function with improper changes, possibly in violation of an implicit or explicit policy. The consequences would only be limited by how the affected data is used, such as an adjacent memory location that is used to specify whether the user has special privileges.
Access Control,Other
Technical Impact: Bypass Protection Mechanism; Other
When the consequence is arbitrary code execution, this can often be used to subvert any other security service.
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