CVE-2026-63687
Apache CXF: JwtRequestCodeFilter silently overrides outer PKCE and nonce parameters
Description
Apache CXF's JwtRequestCodeFilter copies all claims from a signed request JWT into the authorization parameter map without excluding security-sensitive parameters. A client that can produce a validly-signed request JWT (e.g., one whose client_secret is known or compromised) can thereby substitute the code_challenge, code_challenge_method, nonce, and state values that were set in the outer HTTP request, undermining PKCE integrity and OpenID Connect replay protection. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.
INFO
Published Date :
Aug. 6, 2026, 12:16 p.m.
Last Modified :
Aug. 6, 2026, 12:16 p.m.
Remotely Exploit :
No
Source :
[email protected]
Solution
- Upgrade Apache CXF to version 4.2.3 or later.
- Upgrade Apache CXF to version 4.1.8 or later.
- Upgrade Apache CXF to version 3.6.12 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-63687.
| URL | Resource |
|---|---|
| https://lists.apache.org/thread/drcq4chmt0btx86f17o47j17r378hzpw |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63687 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-63687
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-63687 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63687 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Aug. 06, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Apache Software Foundation', 'product': 'Apache CXF', 'versions': [{'status': 'affected', 'version': '4.2.0', 'lessThan': '4.2.3', 'versionType': 'semver'}, {'status': 'affected', 'version': '4.0.0', 'lessThan': '4.1.8', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '3.6.12', 'versionType': 'semver'}], 'packageName': 'org.apache.cxf:cxf-rt-rs-security-oauth2', 'collectionURL': 'https://repo.maven.apache.org/maven2', 'defaultStatus': 'unaffected'}] Added Description Apache CXF's JwtRequestCodeFilter copies all claims from a signed request JWT into the authorization parameter map without excluding security-sensitive parameters. A client that can produce a validly-signed request JWT (e.g., one whose client_secret is known or compromised) can thereby substitute the code_challenge, code_challenge_method, nonce, and state values that were set in the outer HTTP request, undermining PKCE integrity and OpenID Connect replay protection. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue. Added CWE CWE-345 Added Reference https://lists.apache.org/thread/drcq4chmt0btx86f17o47j17r378hzpw