How severe is CVE-2026-66256?

CVE-2026-66256 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-66256 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-66256?

CVE-2026-66256 affects Apache Shindig. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-66256?

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-2026-66256 published?

CVE-2026-66256 was published on 2026-08-13 and last updated on 2026-09-11.

CVE-2026-66256

CVE-2026-66256 is a high-severity vulnerability in Apache Shindig with a CVSS 3.x base score of 7.2. 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-502.

Key facts

Severity: High (CVSS 3.x base score 7.2)
EPSS exploit prediction: 1% (59th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-502
Affected product: Apache Shindig
Published: 2026-08-13
Last modified: 2026-09-11

Description

** UNSUPPORTED WHEN ASSIGNED ** Deserialization of Untrusted Data vulnerability in Apache Shindig. This issue affects Apache Shindig: all versions. Users with access to the Shindig REST API can send specially-crafted requests to trigger arbitrary code execution on the server. As this project is retired, we do not plan to release a version that fixes this issue. Users are recommended to find an alternative or restrict access to the instance to trusted users. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.

Frequently asked questions

What is CVE-2026-66256?: ** UNSUPPORTED WHEN ASSIGNED ** Deserialization of Untrusted Data vulnerability in Apache Shindig. This issue affects Apache Shindig: all versions. Users with access to the Shindig REST API can send specially-crafted requests to trigger arbitrary code execution on the server. As this project is retired, we do not plan to release a version that fixes this issue. Users are recommended to find an alternative or restrict access to the instance to trusted users. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
How severe is CVE-2026-66256?: CVE-2026-66256 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-66256 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-66256?: CVE-2026-66256 affects Apache Shindig. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-66256?: 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-2026-66256 published?: CVE-2026-66256 was published on 2026-08-13 and last updated on 2026-09-11.

References

Affected products (1)

cpe:2.3:a:apache:shindig:*:*:*:*:*:*:*:*

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