How severe is CVE-2021-27098?

CVE-2021-27098 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-27098 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27098?

CVE-2021-27098 affects Cncf Spire. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27098?

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.

When was CVE-2021-27098 published?

CVE-2021-27098 was published on 2021-03-05 and last updated on 2026-06-17.

CVE-2021-27098

CVE-2021-27098 is a high-severity vulnerability in Cncf Spire with a CVSS 3.x base score of 8.1. 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-295.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 5.5
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Cncf Spire
Published: 2021-03-05
Last modified: 2026-06-17

Description

In SPIRE 0.8.1 through 0.8.4 and before versions 0.9.4, 0.10.2, 0.11.3 and 0.12.1, specially crafted requests to the FetchX509SVID RPC of SPIRE Server’s Legacy Node API can result in the possible issuance of an X.509 certificate with a URI SAN for a SPIFFE ID that the agent is not authorized to distribute. Proper controls are in place to require that the caller presents a valid agent certificate that is already authorized to issue at least one SPIFFE ID, and the requested SPIFFE ID belongs to the same trust domain, prior to being able to trigger this vulnerability. This issue has been fixed in SPIRE versions 0.8.5, 0.9.4, 0.10.2, 0.11.3 and 0.12.1.

Frequently asked questions

What is CVE-2021-27098?: In SPIRE 0.8.1 through 0.8.4 and before versions 0.9.4, 0.10.2, 0.11.3 and 0.12.1, specially crafted requests to the FetchX509SVID RPC of SPIRE Server’s Legacy Node API can result in the possible issuance of an X.509 certificate with a URI SAN for a SPIFFE ID that the agent is not authorized to distribute. Proper controls are in place to require that the caller presents a valid agent certificate that is already authorized to issue at least one SPIFFE ID, and the requested SPIFFE ID belongs to the same trust domain, prior to being able to trigger this vulnerability. This issue has been fixed in SPIRE versions 0.8.5, 0.9.4, 0.10.2, 0.11.3 and 0.12.1.
How severe is CVE-2021-27098?: CVE-2021-27098 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-27098 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27098?: CVE-2021-27098 affects Cncf Spire. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27098?: 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.
When was CVE-2021-27098 published?: CVE-2021-27098 was published on 2021-03-05 and last updated on 2026-06-17.

References

https://github.com/spiffe/spire/security/advisories/GHSA-h746-rm5q-8mgq

Affected products (1)

cpe:2.3:a:cncf:spire:*:*:*:*:*:*:*:*

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