CVE-2026-119566

medium

Description

Prometheus through 3.15.1 contains a credential leak vulnerability that allows attackers to capture Azure AD or Google IAM bearer tokens by redirecting remote_write requests to another host. Attackers controlling the remote-write endpoint or a redirecting server can return a 3xx to their host and replay the token, for example to write metrics to the victim's backend.

References

https://www.vulncheck.com/advisories/prometheus-through-3.15.1-credential-leak-via-remote-write-cross-host-redirects

https://github.com/prometheus/prometheus/blob/v3.15.1/storage/remote/client.go#L205-L216

https://github.com/prometheus/prometheus/blob/v3.15.1/storage/remote/azuread/azuread.go#L326-L333

https://github.com/prometheus/prometheus

https://github.com/prometheus/common/pull/901

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-113831

https://abraxaslabs.tech/research/prometheus-bearer-redirect

Details

Source: Mitre, NVD

Published: 2026-10-30

Updated: 2026-10-30

Risk Information

CVSS v2

Base Score: 4

Vector: CVSS2#AV:N/AC:H/Au:N/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 4.8

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Severity: Medium

CVSS v4

Base Score: 6.3

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Severity: Medium

EPSS

EPSS: 0.00201