GHSA-8q6g-vjhf-jp8m

Source

https://github.com/advisories/GHSA-8q6g-vjhf-jp8m

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-8q6g-vjhf-jp8m/GHSA-8q6g-vjhf-jp8m.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-8q6g-vjhf-jp8m

Aliases

CVE-2026-59991

Published

2026-09-22T19:45:51Z

Modified

2026-09-22T20:00:05Z

Severity

7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator

Summary

psd-tools composite/numpy has uncontrolled memory allocation via crafted PSD geometry

Details

Summary

PSDImage.composite() (and .numpy()) allocate the output image buffer from the PSD's header geometry (width × height × channels × depth, and per-layer rectangles) before validating those values against the actual file contents. A tiny crafted PSD declaring huge dimensions causes a multi-gigabyte allocation. Critically, composite() then returns a (black) image with only a warning, no exception is raised, so a caller cannot detect or guard against it.

Impact

On psd-tools 1.17.2 (latest), default usage, a 49-byte PSD makes composite() commit ~3 GB and return successfully (warning only); .numpy() reaches ~7.5 GB, and the per-layer rectangle is a second lever (up to ~32 GB), all from an input under 100 bytes (input-to-commit amplification over 1000×). Because the buffer is committed before validation and no exception is thrown, any service that composites untrusted PSDs is exposed to denial of service: on a host with less RAM than the attacker-declared geometry the allocation is an unrecoverable OOM-kill.

Steps to reproduce

# pip install psd-tools==1.17.2
from psd_tools import PSDImage
psd = PSDImage.open("psd-psdtools-grammar-d23.psd")
psd.composite()   # commits ~3 GB from a 49-byte file and returns (warning only)

PoC (49 bytes), reconstruct with:

base64 -d > psd-psdtools-grammar-d23.psd <<'EOF'
OEJQUwABAAAAAAAAAAYAACg4AAAXTAAIAAMAAAAAAAAAAAAAAAAAAUNIUIFU+yQtDw==
EOF

Verify:

7d8ebf03a54393cb0359ecf4b676d1b08c9a8c6afdd06671ef406d6893cce826  psd-psdtools-grammar-d23.psd

Root cause

The composite/numpy buffer is sized from the declared image (and per-layer) dimensions and channel/depth without checking them against the available data length or a sane maximum.

Suggested fix

Validate the declared dimensions, channel count, and per-layer rectangles against the actual file length (and a configurable maximum pixel/byte budget) before allocating; raise an error on overflow instead of committing the buffer and returning a black image.

Database specific

{
    "cwe_ids":  [
        "CWE-789"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-09-22T19:45:51Z",
    "nvd_published_at":  null,
    "severity":  "HIGH"
}

References

Affected packages

PyPI / psd-tools

Package

Name: psd-tools; View open source insights on deps.dev
Purl: pkg:pypi/psd-tools

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

1.17.4

Affected versions

0.*

0.1.1

0.1.2

0.1.3

0.1.4

0.2

0.5

0.6

0.7

0.7.1

0.8

0.8.1

0.8.2

0.8.3

0.8.4

0.9

0.9.1

0.10

1.*

1.0

1.1

1.2

1.3

1.4

1.8.8

1.8.9

1.8.10

1.8.11

1.8.12

1.8.13

1.8.14

1.8.15

1.8.16

1.8.17

1.8.18

1.8.19

1.8.20

1.8.21

1.8.22

1.8.23

1.8.24

1.8.25

1.8.26

1.8.27

1.8.28

1.8.29

1.8.30

1.8.31

1.8.32

1.8.33

1.8.34

1.8.35

1.8.36

1.8.37

1.8.38

1.9.0

1.9.1

1.9.2

1.9.3

1.9.4

1.9.5

1.9.6

1.9.7

1.9.8

1.9.9

1.9.10

1.9.11

1.9.12

1.9.13

1.9.14

1.9.15

1.9.16

1.9.17

1.9.18

1.9.19

1.9.20

1.9.21

1.9.22

1.9.23

1.9.24

1.9.26

1.9.27

1.9.28

1.9.29

1.9.30

1.9.31

1.9.32

1.9.33

1.9.34

1.10.0

1.10.1

1.10.2

1.10.3

1.10.4

1.10.5

1.10.6

1.10.7

1.10.8

1.10.9

1.10.10

1.10.11

1.10.12

1.10.13

1.11.0

1.11.1

1.12.0

1.12.1

1.12.2

1.13.0

1.13.1

1.14.0

1.14.1

1.14.2

1.14.3

1.15.0.post1

1.16.0

1.17.0

1.17.1

1.17.2

1.17.3

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-8q6g-vjhf-jp8m/GHSA-8q6g-vjhf-jp8m.json"