Deserialization of Untrusted DataWeakness · CWE-502

CVE-2026-66256

HIGH · 7.2 CVSS v3.1 Published 2026-08-13
No fix yet
No fix has been published. The vendor has not shipped a fixed release or patch. You remain exposed.
See remediation →
78/100
Remediation priority · High
Remotely reachable Zero-click 6 days old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
** 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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-502

The application rebuilds objects from attacker-supplied serialized data, and the act of rebuilding can trigger dangerous code paths. In many runtimes this leads straight to remote code execution. The durable fix is to avoid deserializing untrusted input — or to use a strict, type-limited format with integrity checks.

General guidance for the deserialization of untrusted data class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Recommended fix High confidence
  1. 1. Identify and migrate to an alternative solution as Apache Shindig is retired and will not receive security updates.
  2. 2. If continued temporary use is unavoidable, restrict network access to the Shindig REST API by configuring firewall rules to allow only trusted IP addresses.
  3. 3. Apply additional authentication layers such as API keys or mutual TLS for any remaining access.
  4. 4. Prioritize migration to a supported alternative social computing platform.
Caveat No upgrade available - Apache Shindig is retired; migration to an alternative solution is required

Generated from the published advisory — verify against the referenced sources before acting.

No vendor fix exists The vendor has not published a patch for this.

There is no version to upgrade to and no patch to apply. Every affected install stays exposed until the vendor ships a fix — or somebody else builds one.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-66256 in production — separate from our analysis above.

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