Cyber Resilience

CVE-2026-87830

RCE in Apache Wss4J ≤ 2.4.4

RCE
Published
30 September 2026
Modified
06 October 2026
Patch / advisory
View advisory
CVSS Score v3.1 9.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0018 7th percentile
Risk Priority 66 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-87830 is a critical-severity Expression Language Injection (CWE-917) vulnerability in Apache Wss4J. Its CVSS base score is 9.1 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-8 (Security and Privacy Engineering Principles) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

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…

more

encryption. Users are recommended to upgrade to versions 4.0.2 or 3.0.6 or 2.4.4, which fix this issue.

CWE(s)
CWE-917

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-0715Shared CWE-917
CVE-2021-31805Shared CWE-917
CVE-2024-5828Shared CWE-917
CVE-2026-41729Shared CWE-917
CVE-2023-32200Shared CWE-917
CVE-2025-3322Shared CWE-917
CVE-2026-31380Shared CWE-917
CVE-2026-65591Shared CWE-917
CVE-2022-26134Shared CWE-917
CVE-2024-12798Shared CWE-917

Affected Assets

apache
wss4j
≤ 2.4.4 · 3.0.0 — 3.0.6 · 4.0.0 — 4.0.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.3.2
  • V1.3.5
  • V4.3.1

Mitigating Controls (NIST 800-53 r5) AI

SA-8 Security and Privacy Engineering Principles partial match

Security engineering principles include requirements for safe construction and sanitization of dynamic statements, structurally preventing expression-language injection at design time.

SI-10 Information Input Validation partial match

Input validation directly requires checking and neutralizing special elements in externally influenced data before it is used to build executable statements such as EL expressions.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
prevents

Secure SDLC practices directly require input neutralization and safe EL construction to prevent injection flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.5.3 Segregation of duties partial match
removes

References