CVE-2026-66256: UNSUPPORTED WHEN ASSIGNED Deserialization of Untrusted Data vulnerability in Apache Shindig. This issue

Q: How do I fix CVE-2026-66256?

shindig: upgrade to newer than 3.0.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-66256 being exploited?

CVE-2026-66256 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-66256 affect?

CVE-2026-66256 affects shindig. Severity is high (CVSS 7.2). ** 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 a

Q: How urgent is CVE-2026-66256?

Priority 45/100. High severity; On your watchlist

This month

HIGH 7.2WATCHLISTUPGRADE

CVE-2026-66256 is a high-severity flaw (CVSS 7.2) affecting shindig. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

** 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

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	0.9% (top 39%)
CISA exploited list	No
Weakness	CWE-502
Published	2026-08-13
Last modified	2026-09-11

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-09-11 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-13 15:19 UTCPublished CVE record published
2026-09-11 13:53 UTCUpdated Record last modified

apache shindig UPGRADE

Affected: <= 3.0.0

Fixed in: newer than 3.0.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy shindig || rpm -q shindig || shindig --version

2. UPGRADE to newer than 3.0.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade shindig

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade shindig

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-66256?