CVE-2026-66256

HIGHPre-NVD 7.27.2—
EchelonGraph scoreHIGH confidence

Score 7.2 from GitHub Security Advisory (severity: HIGH) published 2026-08-13. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
7.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.2Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
7.2
EG Score
7.2(high)
EG Risk
33(Track)
EG Risk 33/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity72% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
42%
KEV
Not listed

Published

August 13, 2026

Last Modified

August 14, 2026

Advisory Details (1)

Auto-updated Aug 13, 2026
No patch confirmed yet.
generic
https://lists.apache.org/thread/opgpnhk149614gx6vcy3lvyjnycw8mkh

Vendor Advisories for CVE-2026-66256(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 28× in last 7d / 38× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-21 00:30 UTCEG score recompute
  2. 2026-08-21 00:30 UTCGHSA enrichment
  3. 2026-08-20 22:56 UTCEPSS rescore
  4. 2026-08-20 13:07 UTCGHSA enrichment
  5. 2026-08-20 01:27 UTCEG score recompute
  6. 2026-08-20 01:27 UTCGHSA enrichment
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-19 14:02 UTCGHSA enrichment
  9. 2026-08-19 02:35 UTCGHSA enrichment
  10. 2026-08-18 15:03 UTCEG score recompute
  11. 2026-08-18 15:03 UTCGHSA enrichment
  12. 2026-08-18 13:48 UTCEPSS rescore
  13. 2026-08-18 03:14 UTCGHSA enrichment
  14. 2026-08-17 15:48 UTCEG score recompute
  15. 2026-08-17 15:48 UTCGHSA enrichment
  16. 2026-08-17 13:47 UTCEPSS rescore
  17. 2026-08-17 04:24 UTCGHSA enrichment
  18. 2026-08-16 17:00 UTCEG score recompute
  19. 2026-08-16 17:00 UTCGHSA enrichment
  20. 2026-08-16 14:56 UTCEPSS rescore
  21. 2026-08-16 05:35 UTCEG score recompute
  22. 2026-08-16 05:35 UTCGHSA enrichment
  23. 2026-08-15 18:12 UTCGHSA enrichment
  24. 2026-08-15 06:48 UTCEG score recompute
  25. 2026-08-15 06:48 UTCGHSA enrichment
Show 13 more
  1. 2026-08-15 01:30 UTCEPSS rescore
  2. 2026-08-14 19:17 UTCGHSA enrichment
  3. 2026-08-14 16:16 UTCGHSA enrichment
  4. 2026-08-14 04:52 UTCEG score recompute
  5. 2026-08-14 04:52 UTCGHSA enrichment
  6. 2026-08-13 17:28 UTCGHSA enrichment
  7. 2026-08-13 16:26 UTCGHSA enrichment
  8. 2026-08-13 15:57 UTCEG score recompute▲ 7.20
  9. 2026-08-13 15:57 UTCGHSA enrichment
  10. 2026-08-13 15:56 UTCMITRE cvelistV5CVSS v3 → 7.2 · severity → HIGH
  11. 2026-08-13 15:22 UTCNVD update
  12. 2026-08-13 14:22 UTCEG score recompute
  13. 2026-08-13 14:21 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-66256?
CVE-2026-66256 is a high vulnerability published on August 13, 2026. 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,…
When was CVE-2026-66256 disclosed?
CVE-2026-66256 was first published in the National Vulnerability Database on August 13, 2026, with the most recent update on August 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66256 actively exploited?
CVE-2026-66256 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 57.9% of all scored CVEs.
What is the CVSS score of CVE-2026-66256?
CVE-2026-66256 has a CVSS v3.1 base score of 7.2 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-66256?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66256, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-66256

Explore →

Is Your Infrastructure Affected by CVE-2026-66256?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs