CriticalCVE-2026-112403

    Pillow: Heap buffer overflow in ImagingJpegDecode (CVE-2026-112403)

    Published Last modified Sources: pwn.watch, CVE.org, OSV, Hersteller

    What is affected, what to do

    Pillow is a Python imaging library. Prior to 13.0.0, Pillow's JPEG decoder can write a full-width scanline into a buffer sized for a requested draft scale.

    An exploit is publicly available. Update Python-pillow Pillow to version 13.0.0.

    Affected
    • Python-pillow Pillow lt *..13.0.0
    Fixed in
    • Python-pillow Pillow 13.0.0

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

    Metrics

    9.8

    Priority

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

    Source: NVD, CVSS v3

    9.8

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: pwn.watch, CVE.org, OSV, Hersteller

    0.8 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 55.5

    Show all metrics
    Severity
    Critical
    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
    103.61 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
    PoC (publicly reported)
    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
    9.8 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
    9.8
    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
    9.2
    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
    0.8 %
    Low — model estimates < 1% 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
    55.5
    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

    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

    Pillow is a Python imaging library. Prior to 13.0.0, Pillow's JPEG decoder can write a full-width scanline into a buffer sized for a requested draft scale. ImagingJpegDecode does not verify libjpeg's actual output width and component count after scaling is requested, and an 8-bit lossless SOF3 JPEG decoded by a build linked to libjpeg-turbo 3.x can ignore the requested downscaling geometry. An attacker can supply such a JPEG to an application that uses draft() or thumbnail() to request downscaling. This can corrupt heap memory, crash the process, or potentially allow code execution. Older libjpeg-turbo 2.x and IJG builds reject the SOF3 input. This issue is fixed in version 13.0.0.

    Source: pwn.watch, NVD (NIST), OSV (Open Source Vulnerabilities), GitHub Security Advisories, cvelistv5

    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
    python-pillowPillow
    • < 13.0.0
    • 13.0.0
    pythonpillow
    • < 13.0.0
    • 13.0.0
    pipPillow
    • <= 12.3.0
    • 13.0.0
    pypipillow
    • 2.5.2
    • 6.1.0
    • 3.1.0.rc1
    • 10.2.0
    • 2.5.3
    • 1.2
    • 8.0.1
    • 2.1.0
    • 11.3.0
    • 2.5.1
    • 8.3.1
    • 10.4.0
    • 6.0.0
    • 5.1.0
    • 1.4
    • 3.3.1
    • 3.1.2
    • 12.1.0
    • 2.8.0
    • 2.6.1
    • 8.4.0
    • 11.0.0
    • 5.4.0
    • 1.7.8
    • 2.4.0
    • 9.1.1
    • 5.4.0.dev0
    • 2.0.0
    • 9.3.0
    • 1.7.1
    • 2.8.2
    • 1.3
    • 2.3.2
    • 7.1.2
    • 1.7.0
    • 10.0.1
    • 1.7.6
    • 9.0.0
    • 8.0.0
    • 3.1.0rc1
    • 4.1.0
    • 1.7.3
    • 2.2.0
    • 2.2.2
    • 3.0.0
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    Distribution and container packages (1)

    Downstream packages (e.g. Bitnami, Debian, Ubuntu, Red Hat). Versions refer to the distribution, not the vendor.

    Distribution and container packages
    Affected versionsFixed in
    bitnamipillow
    • —
    • 13.0.0

    Vendors and products

    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

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    Reference tagged as exploitgithub.com (opens in a new tab)PoC (publicly reported)reported, not verified—

    References & sources

    • github.compython-pillow/Pillow/commit/242a059aedc1935097d9aa1dc3f09975046…x_refsource_MISC, web, Patch
    • github.compython-pillow/Pillow/releases/tag/13.0.0x_refsource_MISC, web, pwn-watch, Release notes
    • github.compython-pillow/Pillow/security/advisories/GHSA-8g5g-8vmr-9782x_refsource_CONFIRM, web, pwn-watch, Exploit, Vendor advisory
    • NVD (NIST)vuln/detail/CVE-2026-112403advisory, web
    • github.compython-pillow/Pillowpackage
    • pwn.watchpwn.watch: Pillow: heap buffer overflow in FlashPix (FPX) JPEG decoding lets one crafted image run code (CVE-2026-112398)pwn-watch
    • github.comGHSA-5x8w-8jj5-q52h: Heap buffer overflow in FlashPix (FPX) JPEG decoding leads to code executionpwn-watch
    • GitHub Security AdvisoriesGHSA-5x8w-8jj5-q52hpwn-watch
    • NVD (NIST)CVE-2026-112398pwn-watch
    • github.comGHSA-w889-685w-c8fh: Argument Injection in Ghostscript call, potentially leading into RCE (CVE-2026-112900)pwn-watch
    • GitHub Security AdvisoriesGHSA-332p-7hrc-92wf: Heap buffer overflow in _tiffWriteProc when saving TIFF to BytesIO (CVE-2026-112393)pwn-watch
    • pillow.readthedocs.ioPillow 13.0.0 release notes (security section)pwn-watch

    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. Initial analysis by NVDNVD

      Newly listed as affected:

      CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      CVSSadded
      —
      AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
      Product configurationadded
      —
      OR *cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* versions up to (excluding) 13.0.0
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/python-pillow/Pillow/commit/242a059aedc1935097d9aa1dc3f099750467ba75 Types: Patch
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/python-pillow/Pillow/releases/tag/13.0.0 Types: Release Notes
      Reference typeadded
      —
      CISA-ADP: https://github.com/python-pillow/Pillow/security/advisories/GHSA-8g5g-8vmr-9782 Types: Exploit, Vendor Advisory
      Reference typeadded
      —
      GitHub, Inc.: https://github.com/python-pillow/Pillow/security/advisories/GHSA-8g5g-8vmr-9782 Types: Exploit, Vendor Advisory

      Source identifier: nvd@nist.gov

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: proof of concept, automatable: no

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://github.com/python-pillow/Pillow/security/advisories/GHSA-8g5g-8vmr-9782
      SSVC assessmentadded
      —
      {"id":"CVE-2026-112403","role":"CISA Coordinator","options":[{"exploitation":"poc"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-10-22T21:08:31.338410Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    3. ReceivedGitHub

      CVSS V4.0: AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

      Weakness type: CWE-122

      Description added or changed

      Show 7 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      Pillow is a Python imaging library. Prior to 13.0.0, Pillow's JPEG decoder can write a full-width scanline into a buffer sized for a requested draft scale. ImagingJpegDecode does not verify libjpeg's actual output width and component count after scaling is requested, and an 8-bit lossless SOF3 JPEG decoded by a build linked to libjpeg-turbo 3.x can ignore the requested downscaling geometry. An attacker can supply such a JPEG to an application that uses draft() or thumbnail() to request downscaling. This can corrupt heap memory, crash the process, or potentially allow code execution. Older libjpeg-turbo 2.x and IJG builds reject the SOF3 input. This issue is fixed in version 13.0.0.
      CVSSadded
      —
      AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
      Weakness type (CWE)added
      —
      CWE-122
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/112xxx/CVE-2026-112403.json">CVE-2026-112403</a>
      Referenceadded
      —
      https://github.com/python-pillow/Pillow/commit/242a059aedc1935097d9aa1dc3f099750467ba75
      Referenceadded
      —
      https://github.com/python-pillow/Pillow/releases/tag/13.0.0
      Referenceadded
      —
      https://github.com/python-pillow/Pillow/security/advisories/GHSA-8g5g-8vmr-9782

      Source identifier: security-advisories@github.com

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