CVE-2026-18108

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Source
https://cve.org/CVERecord?id=CVE-2026-18108
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-18108.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-18108
Published
2026-08-03T13:00:23.347Z
Modified
2026-08-08T03:30:47.620349354Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
Net::SAML2 versions before 0.86 for Perl allow authentication bypass because _verify_encrypted_assertion accepts an EncryptedAssertion whose decrypted content carries no signature
Details

Net::SAML2 versions before 0.86 for Perl allow authentication bypass because verifyencrypted_assertion accepts an EncryptedAssertion whose decrypted content carries no signature.

verifyencryptedassertion 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 signature is present, so a decrypted assertion with no dsig:Signature element reaches newfrom_xml unverified and its NameID and attributes are read into the assertion object. An SP's encryption certificate is published in its SAML metadata so the IdP can encrypt to it, so any party can encrypt an unsigned assertion to that certificate, wrap it in a samlp:Response, and post it to the assertion consumer service.

Any caller that configures a decryption keyfile, and so accepts EncryptedAssertions, takes identity fields from an assertion that no trust anchor covers, and an unauthenticated party can authenticate as an arbitrary user. Callers with no keyfile configured do not decrypt and are unaffected.

Database specific 
{
    "cwe_ids": [
        "CWE-347"
    ],
    "cna_assigner": "CPANSec",
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "fixed": "0.86"
                }
            ]
        },
        {
            "source": "DESCRIPTION",
            "extracted_events": [
                {
                    "fixed": "0.86"
                }
            ]
        }
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/18xxx/CVE-2026-18108.json"
}
References

Affected packages

Git / github.com/perl-net-saml2/perl-net-saml2

Affected ranges

Type
GIT
Repo
https://github.com/perl-net-saml2/perl-net-saml2
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
d916468586404518b8cf3c78dbd001cc1f1046a7
Database specific 
{
    "source": "REFERENCES"
}

Affected versions

0.*
0.19.05
0.20
0.20.03-TRIAL
0.25
0.29
0.30-TRIAL
0.31-TRIAL
0.32
0.33-TRIAL
0.34
0.35-TRIAL
0.36-TRIAL
0.37-TRIAL
0.38
0.39
0.40
0.41
0.42
0.43
0.44
0.45
0.47
0.48
0.49
0.51
0.52
0.53
0.54
0.55
0.56
0.57
0.58
0.60
0.61
0.62
0.63
0.64
0.65
0.66
0.67
0.68
0.69
0.70
0.71
0.72
0.73
0.74
0.75
0.76
0.77
0.78
0.79
0.80
0.81
0.82
0.83
0.84
0.85
perl-net-saml2-0.*
perl-net-saml2-0.19.05
v0.*
v0.10
v0.11
v0.12
v0.14
v0.15
v0.16
v0.17
v0.17_06
v0.20
v0.26-TRIAL

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-18108.json"