psd-tools is a Python package for working with Adobe Photoshop PSD files. Prior to 1.17.4, PSDImage.composite() and PSDImage.numpy() allocated output buffers from attacker-controlled PSD header geometry, including width, height, channels, depth, and per-layer rectangles, before validating those values against the available file data. A tiny crafted PSD could therefore cause multi-gigabyte memory allocation, and PSDImage.composite() could return a black image with only a warning instead of raising an exception. Services that composite untrusted PSD files could be terminated by out-of-memory handling. This issue is fixed in version 1.17.4.
CVE-2026-59991
HIGHPre-NVD 7.57.5—Trending — 3 sources updated this weekElevated
EchelonGraph scoreMEDIUM confidence
This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 52% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: Elevated riskExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 65(Attend)EG Risk 65/100SSVC: Attend
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation40% × 40%Automatability100% × 15%Action: Remediate soon — notable exploitation risk. - EPSS PROB
- 1%
- EPSS %ILE
- 48%
- KEV
- Not listed
Published
September 22, 2026
Last Modified
September 23, 2026
Advisory Details (3)
Auto-updated Sep 22, 2026🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github_release Patch Available
Release v1.17.4
Patch available: psd-tools/psd-tools v1.17.4
https://github.com/psd-tools/psd-tools/releases/tag/v1.17.4github_commit Patch Available
commit a3d9a53ad51e (psd-tools/psd-tools)
Patch available: psd-tools/psd-tools v1.17.4 (contains commit a3d9a53ad51e)
https://github.com/psd-tools/psd-tools/commit/a3d9a53ad51e667b5772a4f636ca6f2e16f4b271github Patch Available🟡 PoC Available
Uncontrolled memory allocation in psd-tools composite/numpy via crafted PSD geometry · Advisory · psd-tools/psd-tools · GitHub
https://github.com/psd-tools/psd-tools/security/advisories/GHSA-8q6g-vjhf-jp8mVendor Advisories for CVE-2026-59991(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
PyPI(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| psd-tools | 0.1.1 ... 1.9.9 (118 versions) | 1.17.4 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 6× in last 7d / 6× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-23 18:25 UTCEG score recompute
- 2026-09-23 17:54 UTCEPSS rescore
- 2026-09-22 20:32 UTCEG score recompute
- 2026-09-22 19:48 UTCEG score recompute
- 2026-09-22 19:23 UTCEG score recompute
- 2026-09-22 19:23 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-59991?
CVE-2026-59991 is a high vulnerability published on September 22, 2026. psd-tools is a Python package for working with Adobe Photoshop PSD files. Prior to 1.17.4, PSDImage.composite() and PSDImage.numpy() allocated output buffers from attacker-controlled PSD header geometry, including width, height, channels, depth, and per-layer rectangles, before validating those…
When was CVE-2026-59991 disclosed?
CVE-2026-59991 was first published in the National Vulnerability Database on September 22, 2026, with the most recent update on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59991 actively exploited?
CVE-2026-59991 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 52.1% of all scored CVEs.
What is the CVSS score of CVE-2026-59991?
CVE-2026-59991 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-59991?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59991, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-59991
Is Your Infrastructure Affected by CVE-2026-59991?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.