HighCVE-2026-25646

    LIBPNG has a heap buffer overflow in png_set_quantize (CVE-2026-25646)

    Published Last modified Sources: BSI, Red Hat, SUSE, CVE.org, Debian LTS, Debian

    What is affected, what to do

    LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to 1.6.55, an out-of-bounds read vulnerability exists in the png_set_quantize() API function.

    Update Pnggroup Libpng to version 1.6.55.

    Affected
    • Pnggroup Libpng lt *..1.6.55
    Fixed in
    • Pnggroup Libpng 1.6.55

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    8.3

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v4

    8.1

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: BSI, Red Hat, SUSE, CVE.org, Debian LTS, Debian

    1.1 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 65.4

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    89.97 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    8.3 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    8.1
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    8.3
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    1.1 %
    Moderate — model estimates 1-10% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    65.4
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-122, CWE-126

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to 1.6.55, an out-of-bounds read vulnerability exists in the png_set_quantize() API function. When the function is called with no histogram and the number of colors in the palette is more than twice the maximum supported by the user's display, certain palettes will cause the function to enter into an infinite loop that reads past the end of an internal heap-allocated buffer. The images that trigger this vulnerability are valid per the PNG specification. This vulnerability is fixed in 1.6.55.

    Source: BSI WID Portal, BSI CSAF, redhat_csaf, suse_csaf, cvelistv5, NVD (NIST), CVE.org (MITRE), Debian LTS Advisories, Debian Security Advisories

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    pnggrouplibpng
    • < 1.6.55
    • 1.6.55
    libpnglibpng
    • < 1.6.55
    • 1.6.55
    DellSecure Connect Gateway
    • < 5.34.00.16
    • 5.34.00.16
    IBMQRadar SIEM
    • <7.5.0 UP15 IF02
    • —
    IBMSecurity Verify Access
    • < 10.0.9.2
    • 10.0.9.2
    MeinbergLANTIME
    • < 7.10.009
    • 7.10.009
    Open Sourcelibpng
    • < 1.6.55
    • 1.6.55
    OracleCommunications
    • Unified Assurance 6.1.1-7.0.0
    • —
    Red HatOpenShift Container Platform
    • < 4.18.37
    • < 4.17.54
    • < 4.15.64
    • < 4.19.28
    • < 4.13.65
    • 4.18.37
    • 4.17.54
    • 4.15.64
    • 4.19.28
    • 4.13.65
    SecurepointUTM
    • < 14.0.12
    • 14.0.12

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlibpng1.6bookworm
    Linuxdebianlibpng1.6bullseye
    Linuxdebianlibpng1.6trixie

    Weakness classes (CWE)

    • CWE-122Heap-based Buffer Overflow

      Variant

      A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

      Entry at MITRE CWE-122

    • CWE-126Buffer Over-read

      Variant

      The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.

      Entry at MITRE CWE-126

    References & sources

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Record modifiedRed Hat ADP

      7 individual changes: Affected versions (publisher), Reference

      Show 7 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)changed
      OPENJDK ELS 11.0.31, Red Hat Build of OpenJDK 17.0.9, Red Hat Enterprise Linux 10 (+105)
      Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 7 Extended Lifecycle Support (+77)
      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:9254
      —
      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:9255
      —
      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:9683
      —
      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:9686
      —
      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:9687
      —
      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:9689
      —

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    2. Record modifiedRed Hat ADP

      Show 3 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:9683
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:9689
      Affected versions (publisher)changed
      OPENJDK ELS 11.0.31, Red Hat Build of OpenJDK 17.0.9, Red Hat Enterprise Linux 10 (+90)
      OPENJDK ELS 11.0.31, Red Hat Build of OpenJDK 17.0.9, Red Hat Enterprise Linux 10 (+105)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

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