EUVD-2026-70794
GHSA-r9hf-26xj-x88v
Severity by source
AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Network-reachable service accepting a forged token needs no auth or interaction (AV:N/AC:L/PR:N/UI:N); token forgery in a multi-tenant service crosses scope (S:C) with full C/I/A impact.
Primary rating from NVD.
CVSS VectorNVD
Lifecycle Timeline
5DescriptionNVD
Improper verification of cryptographic signature in Copilot Studio allows an unauthorized attacker to elevate privileges over a network.
AnalysisAI
Privilege elevation in Microsoft Copilot Studio lets a network-based, unauthenticated attacker bypass cryptographic signature verification (CWE-347) to gain elevated privileges across a scope boundary, per CVSS:3.1 AV:N/PR:N/S:C rated 10.0. The flaw appears to involve forged or improperly validated JWT tokens, per the 'Jwt Attack' tagging, and because Copilot Studio is a multi-tenant cloud service the scope-change vector implies impact beyond the initially compromised authority. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires network reachability to the Copilot Studio service endpoint that performs the flawed signature check, and the ability to present a crafted token (the 'Jwt Attack' tag points to a JWT). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The signals conflict and must be weighed carefully. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | Because Copilot Studio is a Microsoft-operated cloud service, the fix is delivered service-side by Microsoft; consult the MSRC update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80098 to confirm the mitigation is deployed and whether any tenant-side action is required - Patch available per vendor advisory, with no discrete customer-installable version published. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, contact Microsoft Support to obtain definitive patch status and timeline; implement immediate network-level access restrictions limiting Copilot Studio connections to trusted corporate IP ranges and enforcing VPN-only access; audit Azure AD sign-in logs and Copilot Studio activity logs for suspicious token generation, unauthorized privilege escalation, or unexpected administrative access. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
More in Jwt Attack
View allWhy is Microsoft republishing a CVE from 2013? We are republishing CVE-2013-3900 in the Security Update Guide to update
Authentication bypass in SimpleHelp 5.5.15 and prior (plus 6.0 pre-release builds) allows remote unauthenticated attacke
Authentication bypass in Fortinet FortiOS, FortiProxy, and FortiSwitchManager allows unauthenticated remote attackers to
ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. Rated critical severity (CVS
ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. Rated critical severity (CVS
The package jsrsasign before 10.5.25 are vulnerable to Improper Verification of Cryptographic Signature when JWS or JWT
A library injection vulnerability exists in Microsoft Teams (work or school) 24046.2813.2770.1094 for macOS. Rated criti
A library injection vulnerability exists in the WebView.app helper app of Microsoft Teams (work or school) 24046.2813.27
A library injection vulnerability exists in the com.microsoft.teams2.modulehost.app helper app of Microsoft Teams (work
The Ruby SAML library is for implementing the client side of a SAML authorization. Rated critical severity (CVSS 9.8), t
cosign is a container signing and verification utility. Rated critical severity (CVSS 9.8), this vulnerability is remote
Biscuit is an authentication and authorization token for microservices architectures. Rated critical severity (CVSS 9.8)
Same technique Authentication Bypass
View allShare
External POC / Exploit Code
Leaving vuln.today