CVE-2026-25646Public exploitNetwork attack vector

Application crash via stale palette indices

Published Feb 10, 2026 · Updated Feb 10, 2026

Out-of-bounds read in libpng before 1.6.55 allows attackers to crash consuming applications with a valid crafted PNG image. In png_set_quantize, palette pruning stores current palette indices in a color-distance table, then reuses them after eliminations make them stale, allowing max_d to exceed the 769-entry heap buffer. Exploitation requires a consumer to call the low-level API without a histogram while reducing a palette with more than twice the requested color limit; the published proof of concept demonstrates a crash, while disclosure and code execution remain undemonstrated.

CVSS severity8.3
High
EPSS probability0.97%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in libpng before 1.6.55 allows attackers to crash consuming applications with a valid crafted PNG image. In png_set_quantize, palette pruning stores current palette indices in a color-distance table, then reuses them after eliminations make them stale, allowing max_d to exceed the 769-entry heap buffer. Exploitation requires a consumer to call the low-level API without a histogram while reducing a palette with more than twice the requested color limit; the published proof of concept demonstrates a crash, while disclosure and code execution remain undemonstrated.

The record

CVE
CVE-2026-25646
Published
Feb 10, 2026
Updated
Feb 10, 2026
Vendor
PNG Development Group
Product
libpng
Classifications
CWE-126, CWE-122
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.6.55

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

PNG Development Group · libpngversion=< 1.6.55

Published CVSS scores

7.0Red HatCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
8.3GitHub, Inc.CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
8.1NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-126Buffer Over-read
CWE-122Heap-based Buffer Overflow

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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