CVE-2026-13759

HIGHNVD 8.87.5▼
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-06-30. NVD baseline CVSS 8.8; sources differ by 1.3.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 4 sources updated this week
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.8Exploit: NoneExposed: 0

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

IBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 ships three ObjectInputStream subclasses (WsObjectInputStream, ObjectStreamPool$ReusableInputStream, ObjectInputStreamResolver) that install no JEP-290 class filter; when Coherence is on the classpath, multiple RCE gadget chains including RemoteConstructor.readResolve and PriorityQueue/ExtractorComparator are confirmed working, allowing a post-login attacker who can write a session attribute or a LAN-adjacent attacker on the grid replication wire to execute arbitrary code on peer WAS JVMs

CVSS v3
8.8
EG Score
7.5(medium)
EPSS
22.2%
KEV
Not listed

Published

June 30, 2026

Last Modified

July 3, 2026

Advisory Details (1)

Auto-updated Jun 30, 2026
No patch confirmed yet.
generic

Security Bulletin: IBM WebSphere eXtreme Scale is affected by Insecure Deserilization

https://www.ibm.com/support/pages/node/7278595

Vendor Advisories for CVE-2026-13759(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 34× in last 7d / 34× 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. 2026-07-06 23:12 UTCEG score recompute
  2. 2026-07-06 23:12 UTCGHSA enrichment
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 11:00 UTCEG score recompute
  5. 2026-07-06 11:00 UTCGHSA enrichment
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-05 22:27 UTCEG score recompute
  8. 2026-07-05 22:27 UTCGHSA enrichment
  9. 2026-07-05 10:16 UTCEG score recompute
  10. 2026-07-05 10:16 UTCGHSA enrichment
  11. 2026-07-05 02:30 UTCEPSS rescore
  12. 2026-07-05 02:30 UTCEPSS rescore
  13. 2026-07-04 22:05 UTCEG score recompute
  14. 2026-07-04 22:05 UTCGHSA enrichment
  15. 2026-07-04 09:54 UTCEG score recompute
  16. 2026-07-04 09:54 UTCGHSA enrichment
  17. 2026-07-04 06:31 UTCEPSS rescore
  18. 2026-07-03 21:43 UTCEG score recompute
  19. 2026-07-03 21:43 UTCGHSA enrichment
  20. 2026-07-03 09:32 UTCEG score recompute
  21. 2026-07-03 09:32 UTCGHSA enrichment
  22. 2026-07-02 21:20 UTCEG score recompute
  23. 2026-07-02 21:20 UTCGHSA enrichment
  24. 2026-07-02 20:05 UTCNVD updateCVSS v3 → 8.8
  25. 2026-07-02 09:08 UTCEG score recompute
Show 9 more
  1. 2026-07-02 09:08 UTCGHSA enrichment
  2. 2026-07-01 20:56 UTCEG score recompute
  3. 2026-07-01 20:56 UTCGHSA enrichment
  4. 2026-07-01 15:06 UTCEPSS rescore
  5. 2026-07-01 15:06 UTCEPSS rescore
  6. 2026-07-01 08:45 UTCEG score recompute
  7. 2026-07-01 08:45 UTCGHSA enrichment
  8. 2026-06-30 20:34 UTCEG score recompute
  9. 2026-06-30 20:33 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-13759?
CVE-2026-13759 is a high vulnerability published on June 30, 2026. IBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 ships three ObjectInputStream subclasses (WsObjectInputStream, ObjectStreamPool$ReusableInputStream, ObjectInputStreamResolver) that install no JEP-290 class filter; when Coherence is on the classpath, multiple RCE gadget chains including…
When was CVE-2026-13759 disclosed?
CVE-2026-13759 was first published in the National Vulnerability Database on June 30, 2026, with the most recent update on July 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-13759 actively exploited?
CVE-2026-13759 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 22.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-13759?
CVE-2026-13759 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 7.5.
How do I remediate CVE-2026-13759?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-13759, 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

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