7.2
HIGH CVSS 3.1
CVE-2026-66256
Apache Shindig Common, Apache Shindig Social-Api: Remote Code Execution via XStream deserialization (OpenSocial REST API)
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.

INFO

Published Date :

Aug. 13, 2026, 3:19 p.m.

Last Modified :

Sept. 11, 2026, 1:53 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-66256 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Apache shindig
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 134c704f-9b21-4f2e-91b3-4a467353bcc0
Solution
Restrict access to the Shindig REST API and consider migrating to an alternative solution.
  • Restrict access to the Shindig REST API.
  • Migrate to an alternative, supported solution.
  • Isolate the vulnerable instance.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-66256.

URL Resource
https://lists.apache.org/thread/opgpnhk149614gx6vcy3lvyjnycw8mkh Mailing List Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/08/13/7 Mailing List Third Party Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-66256 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-66256 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-66256 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-66256 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Reanalysis by [email protected]

    Sep. 11, 2026

    Action Type Old Value New Value
    Changed CPE Configuration OR *cpe:2.3:a:apache:shindig:*:*:*:*:*:*:*:* versions up to (including) 2.5.2 OR *cpe:2.3:a:apache:shindig:*:*:*:*:*:*:*:* versions up to (including) 3.0.0
  • Initial Analysis by [email protected]

    Sep. 11, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:apache:shindig:*:*:*:*:*:*:*:* versions up to (including) 2.5.2
    Added Reference Type Apache Software Foundation: https://lists.apache.org/thread/opgpnhk149614gx6vcy3lvyjnycw8mkh Types: Mailing List, Vendor Advisory
    Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/08/13/7 Types: Mailing List, Third Party Advisory
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Aug. 13, 2026

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2026/08/13/7
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 13, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
    Added SSVC {'id': 'CVE-2026-66256', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-13T15:53:08.626107Z'}
  • New CVE Received by [email protected]

    Aug. 13, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'Apache Software Foundation', 'product': 'Apache Shindig Common', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '*'}], 'packageName': 'org.apache.shindig:shindig-common', 'collectionURL': 'https://repo.maven.apache.org/maven2', 'defaultStatus': 'unaffected'}, {'vendor': 'Apache Software Foundation', 'product': 'Apache Shindig Social-Api', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '*'}], 'packageName': 'org.apache.shindig:shindig-social-api', 'collectionURL': 'https://repo.maven.apache.org/maven2', 'defaultStatus': 'unaffected'}]
    Added Tag unsupported-when-assigned
    Added 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.
    Added CWE CWE-502
    Added Reference https://lists.apache.org/thread/opgpnhk149614gx6vcy3lvyjnycw8mkh
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.