High severity · published Mar 26, 2026
CVE-2026-28377
S3 SSE-C Encryption Key Exposed in Plaintext via Config Endpoint (CVE-2025-41118 Pattern)
7.5
CVSS
0.2%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 5% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GR
Grafana · Grafana
2.10.3 · source: vendor
TE
Tempo · Grafana
before 2.10.3 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-28377
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-28377
Vendor Advisory
https://grafana.com/security/security-advisories/cve-2026-28377
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