ZDF
Sign inSign up

Vulnerabilities

Security fix · CVE-2026-96636

Pillow is a Python imaging library.

Published Oct 21, 2026 · catalog updated Oct 28, 2026 · Red Hat Red Hat Enterprise Linux

Last checked Oct 31, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-96636. EPSS is 0.34%. Act only if a listed version of Red Hat Red Hat Enterprise Linux is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium6.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.34%
Remediation
Version ranges on file
Affected products
PyPI pillow · package pip · pip Pillow · pypi pillow

### Summary Pillow's decompression-bomb protection ( , gated by ) is enforced only on the **first frame**, inside . For multi-frame formats, re-parses the target frame's header and resets . and re-run the bomb check on , but ** and do not.** A crafted MPO or DCX whose first frame is tiny (passing the check) but whose later frame declares enormous dimensions therefore bypasses the protection: loading that frame decodes an over-limit image and commits large amounts of memory — a denial of service (memory exhaustion / OOM). Same class as the recently assigned CVE-2026-55379 (BdfFontFile), CVE-2026-55380 (GdImageFile) and CVE-2026-40192 (FITS GZIP). ### Details → runs once, on the frame present at open time. Both vulnerable methods re-parse a new frame and set a new without re-checking: - ** , **: calls (which sets from the frame's JPEG SOF) and rebuilds , with no . - ** , **: calls (which sets from the page's PCX header), with no check. Confirmed present in **12.3.0** (latest release) and on ** ** (13.0.0.dev0). Compare and , which call correctly on seek. ### PoC Self-contained; the victim uses **default** : Measured on Pillow 12.3.0 (default limit 89,478,485 px; error threshold 178,956,970 px): | Vector | File size | Frame 1 | Peak RSS | |---|---|---|---| | MPO (JPEG) | ~3.0 MB | 14000×14000 (196 Mpx) | ~763 MB | | DCX (PCX) | ~6.2 MB | 14000×14000 (196 Mpx) | ~200 MB | | Control: same image standalone | — | 196 Mpx | (correctly blocked) | The DCX vector ( magic + offset directory + two PCX pages) behaves identically via . Scaling frame 1 toward JPEG's ~65500×65500 maximum drives multi-GB commitments from a small file, reliably OOM-killing the process. ### Impact Denial of service (memory exhaustion / OOM) — CWE-400 / CWE-1284, a bypass of Pillow's documented decompression-bomb mitigation. + is the normal way to iterate frames (e.g. , thumbnailers, converters, 3D-photo handlers). Because **MPO is auto-detected from a JPEG carrying MPF metadata**, a file served with a

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • PyPI pillow0 → 13.0.0
  • package pipversion unspecified
  • pip Pillow< 13.0.0
  • pypi pillowversion unspecified

How to fix CVE-2026-96636

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-96636. EPSS is 0.34%. Act only if a listed version of Red Hat Red Hat Enterprise Linux is installed.

Which versions are affected?

Compare what you have installed with Pillow < 13.0.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-400: Uncontrolled Resource Consumption; CWE-409. EPSS 0.34%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Pillow security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 21, 2026 · NIST NVD

    Detected

    Pillow is a Python imaging library. Prior to 13.0.0, MpoImageFile.seek() and DcxImageFile.seek() reparse later MPO or DCX frames and replace self._size without rerunning Image._decompression_bomb_check(). A crafted multi-frame image can use a tiny first frame to pass Image.open() and then declare an over-limit later frame. Normal frame iteration through seek(), load(), or ImageSequence.Iterator ca

  2. Oct 22, 2026 · GitHub Advisory Database

    Updated

    ### Summary Pillow's decompression-bomb protection ( , gated by ) is enforced only on the **first frame**, inside . For multi-frame formats, re-parses the target frame's header and resets . and re-run the bomb check on , but ** and do not.** A crafted MPO or DCX whose first frame is tiny (passing the check) but whose later frame declares enormous dimensions therefore bypasses the protection: loadi

  3. Oct 28, 2026 · PyPA Advisory Database

    Fix available

    pillow fixed in 13.0.0

  4. Oct 28, 2026 · PyPA Advisory Database

    Fix available

    pillow fixed in 13.0.0

  5. Oct 28, 2026 · PyPA Advisory Database

    Updated

    ### Summary Pillow's decompression-bomb protection ( , gated by ) is enforced only on the **first frame**, inside . For multi-frame formats, re-parses the target frame's header and resets . and re-run the bomb check on , but ** and do not.** A crafted MPO or DCX whose first frame is tiny (passing the check) but whose later frame declares enormous dimensions therefore bypasses the protection: loadi

Sources

  • CVE.orgVulnerability recordCVE-2026-96636

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-96636

    30-day exploitation probability 0.34%

    first.org
  • GitHub Advisory DatabasePackage advisoryGHSA-p8hx-v2p6-rp84

    Pillow: Decompression-bomb protection bypass via multi-frame seek() in MPO and DCX (MpoImageFile.seek / DcxImageFile.seek)

    github.com
  • GitLab Advisory DatabasePackage advisoryCVE-2026-96636

    Pillow's decompression-bomb protection (Image._decompression_bomb_check, gated by Image.MAX_IMAGE_PIXELS) is enforced only on the first frame, inside Image.open(). For multi-frame formats, seek() re-parses the target frame's header and resets self._size. GifImagePlugin and TiffImagePlugin re-run the bomb check on seek(), but MpoImageFile.seek() and DcxImageFile.seek() do not. A crafted MPO or DCX

    advisories.gitlab.com
  • NIST NVDVulnerability recordCVE-2026-96636

    Pillow is a Python imaging library. Prior to 13.0.0, MpoImageFile.seek() and DcxImageFile.seek() reparse later MPO or DCX frames and replace self._size without rerunning Image._decompression_bomb_check(). A crafted multi-frame image can use a tiny first frame to pass Image.open()

    nvd.nist.gov
  • PyPA Advisory DatabasePackage advisoryGHSA-p8hx-v2p6-rp84

    Pillow: Decompression-bomb protection bypass via multi-frame seek() in MPO and DCX (MpoImageFile.seek / DcxImageFile.seek)

    osv.dev
  • Red Hat Security DataVendor advisoryCVE-2026-96636

    pillow: pillow: Denial of Service via decompression bomb check bypass in multi-frame images

    access.redhat.com
  • Snyk Vulnerability DatabasePackage advisorySNYK-PYTHON-PILLOW-21431022

    Improper Handling of Highly Compressed Data (Data Amplification)

    security.snyk.io

References

Freshness

Last verified in this catalog Oct 31, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • PyPA Advisory DatabaseOct 28, 2026
  • FIRST EPSSOct 28, 2026
  • Snyk Vulnerability DatabaseOct 24, 2026
  • GitLab Advisory DatabaseOct 23, 2026
  • GitHub Advisory DatabaseOct 23, 2026
  • Red Hat Security DataOct 23, 2026
  • CVE.orgOct 22, 2026
  • NIST NVDOct 22, 2026