PatchTheCVECVE-2026-18108: Net::SAML2 versions before 0.86 for Perl allow authentication bypass because _verify_encrypted_assertion accep
48
This month
CRITICAL 9.8REMOTEUPGRADE
CVE-2026-18108 is a critical-severity flaw (CVSS 9.8) affecting net\. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Net::SAML2 versions before 0.86 for Perl allow authentication bypass because _verify_encrypted_assertion accepts an EncryptedAssertion whose decrypted content carries no signature. _verify_encrypted_assertion decrypts the EncryptedAssertion and returns it as verified when it carries no signature, via "return $xml unless $xpath->exists('dsig:Signature', $assert);". The signature check and the trust anchor check that follow run only when a signatu
Why this priority
- Critical severity
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.3% (top 77%) |
| CISA exploited list | No |
| Weakness | CWE-347 |
| Published | 2026-08-03 |
| Last modified | 2026-10-23 |
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
timlegge net\ UPGRADE
Affected: < 0.86
Fixed in: 0.86
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy net || rpm -q net || net --version
2. UPGRADE to 0.86 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade net
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade net
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
Exact fixes by distribution
Fedora 46 · kwin-zones · FIXED · 1.0.13-1.fc46 · FEDORA-2026-95888f332b · source
sudo dnf upgrade --advisory=FEDORA-2026-95888f332b
Fedora ELN · nginx-mod-brotli · FIXED · 1.0.0~rc-16.eln159 · FEDORA-2026-501a6a8273 · source
sudo dnf upgrade --advisory=FEDORA-2026-501a6a8273
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-2026-18089 HIGH 7.5 UPGRADE Net::SAML2 versions before 0.86 for Perl allow SAML authentication bypass by verifying responses against the r
- CVE-2026-18092 HIGH 8.1 UPGRADE Net::SAML2 versions before 0.86 for Perl allow SAML authentication bypass via XML signature wrapping because n