SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-28377

A vulnerability in Grafana Tempo exposes the S3 SSE-C encryption key in plaintext through the /status/config endpoint, potentially allowing unauthorized users to obtain the key used to encrypt trace data stored in S3.

HIGH 7.5EPSS 0.15%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A vulnerability in Grafana Tempo exposes the S3 SSE-C encryption key in plaintext through the /status/config endpoint, potentially allowing unauthorized users to obtain the key used to encrypt trace data stored in S3. Thanks to william_goodfellow for reporting this vulnerability.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
0.15% probability · 5th percentile
CISA KEV
Not listed
Weakness
CWE-326
Affected
grafana/tempo
Source
security@grafana.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.