GHSA-8q6g-vjhf-jp8m: psd-tools (CVE-2026-59991)

Package	Ecosystem	Affected	Fixed in
psd-tools	PyPI	<1.17.4	1.17.4

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

psd-tools versions before 1.17.4 are vulnerable. The PSDImage.composite() and .numpy() methods allocate the output buffer from the file's declared dimensions before checking them against the actual file contents, so a very small crafted PSD can cause a multi-gigabyte allocation. An attacker who can get the application to process a crafted PSD can cause denial of service, potentially an out-of-memory kill of the host. Upgrade to psd-tools 1.17.4 or later. The source gives no other workaround.

Written 1 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
7.5	High	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0052, the 44th percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:09 UTC First seen by agentprime
31 Oct 2026, 14:09 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.