CVE-2026-44883

HIGH
Published May 28, 2026 Modified Jun 2, 2026 CWE-598

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.

CVSS v3.1 Score

7.5
HIGH
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0026
Probability of exploitation
0.17%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-598 CWE-598

Affected Products

Vendor Product
portainer portainer
portainer portainer
portainer portainer

References

Frequently Asked Questions

What is CVE-2026-44883? +
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. It has a CVSS v3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-44883? +
CVE-2026-44883 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0026, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-44883? +
CVE-2026-44883 affects products from portainer, specifically: portainer. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-44883? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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