CVE-2026-87830

Apache WSS4J: Streaming WS-SecurityPolicy validation may skip element-protection checks.

9.1 Critical

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: None

Exploit likelihood

0.22%Down 0.1 points since Oct 1, 2026

What each source reports

CVE List Score used 9.1

Apache WSS4J: Streaming WS-SecurityPolicy validation may skip element-protection checks.

Record: CVE-2026-87830
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-917
Updated: 2026-11-02

EUVDEUVD-2026-89792 9.1

Record: EUVD-2026-89792
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-66vg-36xv-j6x4 9.1

In the StAX streaming WS-SecurityPolicy validator, certain relative or unsupported XPath...

Record: GHSA-66vg-36xv-j6x4
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-917
Updated: 2026-11-02

NVD 9.1

Record: CVE-2026-87830
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-917
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-87830 9.1

Record: DEBIAN-CVE-2026-87830
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-87830 9.1

Record: UBUNTU-CVE-2026-87830
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Updated: 2026-11-04

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`wss4j` Debian:13	All versions, plus listed versions 1.6.19-4	None known
`wss4j` Debian:14	All versions, plus listed versions 1.6.19-4	None known
`wss4j` Ubuntu:16.04:LTS	All versions, plus listed versions 1.6.15-2	None known
`wss4j` Ubuntu:20.04:LTS	All versions, plus listed versions 1.6.19-2	None known
`wss4j` Ubuntu:24.04:LTS	All versions, plus listed versions 1.6.19-3	None known
`wss4j` Ubuntu:26.10	All versions, plus listed versions 1.6.19-4build1	None known
`wss4j` Ubuntu:26.04:LTS	All versions, plus listed versions 1.6.19-41.6.19-4build1	None known

History

History
Recorded	Changed	Sources
Nov 4, 2026	affected, facts	OSV
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-87830 is a critical vulnerability (CVSS 9.1) in Apache Wss4j, published September 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.22%, the 12th percentile. No source names a fixed version.