CVE-2026-28377
CVE-2026-28377 is a high-severity vulnerability in Grafana Tempo with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-326.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- EPSS exploit prediction: 0% (5th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-16424
- Weakness: CWE-326
- Affected product: Grafana Tempo
- Published:
- Last modified:
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.
Frequently asked questions
- What is 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. Thanks to william_goodfellow for reporting this vulnerability.
- How severe is CVE-2026-28377?
- CVE-2026-28377 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2026-28377 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-28377?
- CVE-2026-28377 affects Grafana Tempo. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2026-28377?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-28377 have an EU (EUVD) identifier?
- Yes. CVE-2026-28377 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16424.
- When was CVE-2026-28377 published?
- CVE-2026-28377 was published on 2026-03-26 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:grafana:tempo:*:*:*:*:*:*:*:*
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