How severe is CVE-2026-23556?

CVE-2026-23556 has a CVSS 4.0 base score of 9.4, rated critical severity.

Is CVE-2026-23556 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-23556?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-23556 published?

CVE-2026-23556 was published on 2026-07-09.

CVE-2026-23556

CVE-2026-23556 is a critical-severity vulnerability with a CVSS 4.0 base score of 9.4. 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-281.

Key facts

Severity: Critical (CVSS 4.0 base score 9.4)
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-281
Published: 2026-07-09
Last modified: 2026-07-09

Description

When oxenstored is tearing a domain down, the node data is cleaned up but the usage counts are leaked. When the domain ID is eventually reused, the new domain can create fewer nodes before beeing deemed to be over quota.

Frequently asked questions

What is CVE-2026-23556?: When oxenstored is tearing a domain down, the node data is cleaned up but the usage counts are leaked. When the domain ID is eventually reused, the new domain can create fewer nodes before beeing deemed to be over quota.
How severe is CVE-2026-23556?: CVE-2026-23556 has a CVSS 4.0 base score of 9.4, rated critical severity.
Is CVE-2026-23556 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-23556?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-23556 published?: CVE-2026-23556 was published on 2026-07-09.

References

Other CWE-281 (Improper Preservation of Permissions) vulnerabilities

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