CVE-2026-87830

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreHIGH confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-30. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 5 sources updated this week
9.1EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 9.1Exploit: None knownExposed services: Not assessed

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

In the StAX streaming WS-SecurityPolicy validator, certain relative or unsupported XPath expressions can be converted into paths that never match the actual XML element path. A remote SOAP peer may therefore send a required element without the expected signature or encryption. Users are recommended to upgrade to versions 4.0.2 or 3.0.6 or 2.4.4, which fix this issue.

CVSS v3
9.1
EG Score
9.1CRITICALhigh confidence
EG Risk
56
EG Risk 56/100CISA SSVC

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
Severity91% × 45%
Exploitation0% × 40%
Automatability100% × 15%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
0.2%
EPSS %ILE
7th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 30, 2026

Last Modified

September 30, 2026

Advisory Details (1)

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

Pony Mail

https://lists.apache.org/thread.html/lwlozb1x20d16f9dnyvoygc9rrhzq2vn

Vendor Advisories for CVE-2026-87830(1)

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

Affected Packages

(2 across 2 ecosystems)
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
wss4j1.6.19-4
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
wss4j1.6.19-4
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 45× in last 7d / 45× 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. 2026-10-05 11:54 UTCGHSA enrichment
  2. 2026-10-05 08:06 UTCGHSA enrichment
  3. 2026-10-05 04:18 UTCGHSA enrichment
  4. 2026-10-05 00:31 UTCEG score recompute
  5. 2026-10-05 00:31 UTCGHSA enrichment
  6. 2026-10-04 23:22 UTCEPSS rescore
  7. 2026-10-04 20:43 UTCGHSA enrichment
  8. 2026-10-04 16:56 UTCGHSA enrichment
  9. 2026-10-04 13:07 UTCGHSA enrichment
  10. 2026-10-04 09:16 UTCGHSA enrichment
  11. 2026-10-04 05:28 UTCGHSA enrichment
  12. 2026-10-04 01:41 UTCGHSA enrichment
  13. 2026-10-03 21:52 UTCGHSA enrichment
  14. 2026-10-03 17:57 UTCEG score recompute
  15. 2026-10-03 17:56 UTCGHSA enrichment
  16. 2026-10-03 14:09 UTCGHSA enrichment
  17. 2026-10-03 10:21 UTCGHSA enrichment
  18. 2026-10-03 06:33 UTCGHSA enrichment
  19. 2026-10-03 02:45 UTCGHSA enrichment
  20. 2026-10-02 22:57 UTCGHSA enrichment
  21. 2026-10-02 19:10 UTCEG score recompute
  22. 2026-10-02 19:10 UTCGHSA enrichment
  23. 2026-10-02 15:21 UTCGHSA enrichment
  24. 2026-10-02 11:31 UTCGHSA enrichment
  25. 2026-10-02 07:39 UTCGHSA enrichment
Show 20 more
  1. 2026-10-02 03:52 UTCGHSA enrichment
  2. 2026-10-02 00:01 UTCEG score recompute
  3. 2026-10-02 00:01 UTCGHSA enrichment
  4. 2026-10-01 19:51 UTCEPSS rescore
  5. 2026-10-01 19:24 UTCGHSA enrichment
  6. 2026-10-01 15:33 UTCGHSA enrichment
  7. 2026-10-01 11:39 UTCGHSA enrichment
  8. 2026-10-01 07:49 UTCGHSA enrichment
  9. 2026-10-01 04:01 UTCGHSA enrichment
  10. 2026-10-01 00:14 UTCEG score recompute
  11. 2026-10-01 00:14 UTCGHSA enrichment
  12. 2026-09-30 20:22 UTCGHSA enrichment
  13. 2026-09-30 19:51 UTCEG score recompute▲ 9.10
  14. 2026-09-30 19:51 UTCGHSA enrichment
  15. 2026-09-30 19:50 UTCMITRE cvelistV5CVSS v3 → 9.1 · severity → CRITICAL
  16. 2026-09-30 16:23 UTCGHSA enrichment
  17. 2026-09-30 13:23 UTCGHSA enrichment
  18. 2026-09-30 12:20 UTCNVD update
  19. 2026-09-30 12:02 UTCEG score recompute
  20. 2026-09-30 12:02 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-87830?
CVE-2026-87830 is a critical vulnerability published on September 30, 2026. In the StAX streaming WS-SecurityPolicy validator, certain relative or unsupported XPath expressions can be converted into paths that never match the actual XML element path. A remote SOAP peer may therefore send a required element without the expected signature or encryption. Users are recommended…
When was CVE-2026-87830 disclosed?
CVE-2026-87830 was first published on September 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-87830 actively exploited?
CVE-2026-87830 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (7th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-87830?
CVE-2026-87830 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-87830?
No fix for CVE-2026-87830 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-87830 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-87830

Explore →

Is Your Infrastructure Affected by CVE-2026-87830?

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

Book a Demo →Browse All CVEs