How severe is CVE-2026-55998?

CVE-2026-55998 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2026-55998 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-55998?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-55998 published?

CVE-2026-55998 was published on 2026-08-05.

CVE-2026-55998

CVE-2026-55998 is a medium-severity vulnerability with a CVSS 3.x base score of 5.3. 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-204.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (11th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-204
Published: 2026-08-05
Last modified: 2026-08-05

Description

The endpoint /v3/import/{token}_{clusterId}.yaml retrieves the cluster object before validating the token. When a valid cluster ID references a cluster that has private registry secrets configured, a nil pointer dereference in pkg/systemtemplate/private_registry.go causes the request to return HTTP 502 Bad Gateway. For cluster IDs that do not exist, the endpoint returns HTTP 200. This observable difference in response codes constitutes a reliable enumeration oracle.

Frequently asked questions

What is CVE-2026-55998?: The endpoint /v3/import/{token}_{clusterId}.yaml retrieves the cluster object before validating the token. When a valid cluster ID references a cluster that has private registry secrets configured, a nil pointer dereference in pkg/systemtemplate/private_registry.go causes the request to return HTTP 502 Bad Gateway. For cluster IDs that do not exist, the endpoint returns HTTP 200. This observable difference in response codes constitutes a reliable enumeration oracle.
How severe is CVE-2026-55998?: CVE-2026-55998 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2026-55998 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-55998?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-55998 published?: CVE-2026-55998 was published on 2026-08-05.

References

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