How severe is CVE-2026-66766?

CVE-2026-66766 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 none, integrity none, and availability high.

Is CVE-2026-66766 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.

How do I fix CVE-2026-66766?

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-2026-66766 published?

CVE-2026-66766 was published on 2026-08-25 and last updated on 2026-08-26.

CVE-2026-66766

CVE-2026-66766 is a high-severity vulnerability 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-1333.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1333
Published: 2026-08-25
Last modified: 2026-08-26

Description

SAP S/4HANA (Private Cloud) uses a third-party component that contains a Regular Expression Denial of Service (ReDoS) vulnerability. An unauthenticated attacker could supply specially crafted input that triggers excessive processing within the affected functionality. Successful exploitation could exhaust system resources and make the service unavailable, resulting in a high impact on availability. There is no impact on confidentiality and integrity.

Frequently asked questions

What is CVE-2026-66766?: SAP S/4HANA (Private Cloud) uses a third-party component that contains a Regular Expression Denial of Service (ReDoS) vulnerability. An unauthenticated attacker could supply specially crafted input that triggers excessive processing within the affected functionality. Successful exploitation could exhaust system resources and make the service unavailable, resulting in a high impact on availability. There is no impact on confidentiality and integrity.
How severe is CVE-2026-66766?: CVE-2026-66766 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 none, integrity none, and availability high.
Is CVE-2026-66766 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.
How do I fix CVE-2026-66766?: 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-2026-66766 published?: CVE-2026-66766 was published on 2026-08-25 and last updated on 2026-08-26.

References

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