CVE-2026-54782
CoreWCF SAML token validation bypass allows identity impersonation.
Is CVE-2026-54782 being exploited?
Not confirmed. CVE-2026-54782 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.41% probability of exploitation in the next 30 days.
How severe is CVE-2026-54782?
CVE-2026-54782 is rated Critical with a CVSS score of 10.0. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-54782?
Yes. A fix has been recorded for CVE-2026-54782. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-54782 affect?
CVE-2026-54782 affects CoreWCF <1.8.1 and <1.9.1, Apps using CoreWCF IdentityConfiguration with federated bindings, SAML 1.1/2.0 token validation in CoreWCF. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-54782?
Upgrade CoreWCF to 1.8.1 or 1.9.1; disable federated SAML bindings until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated attacker can bypass SAML 1.1/2.0 validation in CoreWCF with IdentityConfiguration/federated bindings to impersonate any principal issued by a trusted STS.
Immediate action required
- affected>= 1.9.0 and < 1.9.1
- affected< 1.8.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.