CVE-2025-64505

LIBPNG is vulnerable to a heap buffer overflow in `png_do_quantize` via malformed palette index

MEDIUM
6.1
CVSS Score
Published: November 24, 2025 at 11:38 PM UTC
Updated: October 18, 2026 at 08:10 PM UTC
2 products affected across 2 vendorsLibpngLibpng

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Severity
MEDIUM6.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to version 1.6.51, a heap buffer over-read vulnerability exists in libpng's png_do_quantize function when processing PNG files with malformed palette indices. The vulnerability occurs when palette_lookup array bounds are not validated against externally-supplied image data, allowing an attacker to craft a PNG file with out-of-range palette indices that trigger out-of-bounds memory access. This issue has been patched in version 1.6.51.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.6.51
v < 1.6.51
Affected range stops below 1.6.51, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/pnggroup/libpng/security/advisories/GHSA-4952-h5wq-4m42
x_refsource_MISCIssue Tracking
Source: cverecord
https://github.com/pnggroup/libpng/pull/748

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.1MEDIUMGitHub_M
Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-125

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