Is CVE-2026-23897 in the CISA KEV catalog?

No. CVE-2026-23897 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-23897?

CVE-2026-23897 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2026-23897?

CVE-2026-23897 has an EPSS score of 0.63% (45th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-23897

HIGH

7.5

CVSS v3

NVD

Description

Apollo Server is an open-source, spec-compliant GraphQL server that's compatible with any GraphQL client, including Apollo Client. In versions from 2.0.0 to 3.13.0, 4.2.0 to before 4.13.0, and 5.0.0 to before 5.4.0, the default configuration of startStandaloneServer from @apollo/server/standalone is vulnerable to denial of service (DoS) attacks through specially crafted request bodies with exotic character set encodings. This issue does not affect users that use @apollo/server as a dependency for integration packages, like @as-integrations/express5 or @as-integrations/next, only direct usage of startStandaloneServer.

CWE-1333

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

0.63%probability of exploitation in 30 days

45thpercentile

Moderate risk: more likely to be exploited than 45% of all known CVEs.

References

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-03-18.