PatchTheCEVCVE-2026-63687: Apache CXF's JwtRequestCodeFilter copies all claims from a signed request JWT into the authorization parameter
50
This month
CRITICAL 9.1REMOTEWATCHLISTUPGRADE
CVE-2026-63687 is a critical-severity flaw (CVSS 9.1) affecting cxf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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 Connec
Why this priority
- Critical severity
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.1 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 80%) |
| CISA exploited list | No |
| Weakness | CWE-345 |
| Published | 2026-08-06 |
| Last modified | 2026-10-23 |
Publisher (CNA): Apache Software Foundation · Vendor: apache
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
apache cxf UPGRADE
Affected: < 3.6.12 · >= 4.0.0 and < 4.1.8 · >= 4.2.0 and < 4.2.3
Fixed in: 3.6.12, 4.1.8, 4.2.3
Safe to downgrade to: a release before 4.0.0
1. Check installed version
apt-cache policy cxf || rpm -q cxf || cxf --version
2. UPGRADE to 3.6.12 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade cxf
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade cxf
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
3. If no update is available yet, DOWNGRADE to a release before 4.0.0 (Debian / Ubuntu)
apt-cache madison cxf
sudo apt install cxf=<VERSION_BEFORE_4.0.0>
sudo apt-mark hold cxf
3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list cxf
sudo dnf downgrade cxf-<VERSION_BEFORE_4.0.0>
sudo dnf versionlock add cxf
Downgrade risk
Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.
After downgrade
Restart the service, and keep the package held until a fixed release ships.
Exact fixes by distribution
Fedora 46 · rubygem-eventmachine · FIXED · 1.2.7-37.fc46 · FEDORA-2026-7194c202a2 · source
sudo dnf upgrade --advisory=FEDORA-2026-7194c202a2
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Related CVEs
- CVE-2026-66909 CRITICAL 9.8 UPGRADE Apache CXF's JMS transport deserializes the body of any inbound JMS ObjectMessage using native Java deserializ
- CVE-2026-68079 CRITICAL 9.8 UPGRADE In Apache CXF's DefaultEncryptingCodeDataProvider, a captured authorization code can be redeemed an unlimited
- CVE-2026-61466 CRITICAL 9.1 UPGRADE In Apache CXF's OAuth2 Dynamic Client Registration endpoint, the authorization server accepts and stores the `
- CVE-2026-57817 HIGH 8.1 UPGRADE The OpenID Connect Core 1.0 specification mandates that the RP MUST validate the `c_hash` parameter when opera
- CVE-2026-54225 HIGH 7.5 UPGRADE Apache CXF allows to control the maximum attachment size via the "attachment-max-size"