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Fencer Intel
high 7.5

CVE-2026-28377 json

S3 SSE-C Encryption Key Exposed in Plaintext via Config Endpoint (CVE-2025-41118 Pattern)

published 7mo ago modified last mo. also GHSA-ffqx-q65f-36jf , GO-2026-5359 , EUVD-2026-16424

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

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.

Patch / fix

  • go github.com/grafana/tempo 2.10.3
  • grafana tempo 2.10.3
  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • tempo-cli openSUSE Tumbleweed 2.10.3-1.1

opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2026:10390-1

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-28377 updated cvss 6.5

Grafana Tempo: Grafana Tempo: Information disclosure of S3 encryption key via status config endpoint

  • Red Hat Enterprise Linux 8 grafana, grafana-loki, grafana-mssql, grafana-mysql, grafana-selinux, grafana-graphite, +8 more Red Hat Enterprise Linux 9 grafana, grafana-selinux Red Hat Enterprise Linux 10 grafana
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/acm-grafana-rhel9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
7mo ago

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
go github.com/grafana/tempo
<2.10.3
all versions
2.10.3

Affected products

  • Grafana Tempo

Classification

Weakness
  • CWE-326 Inadequate Encryption Strength

References

Sources

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