CVE-2026-32726

HighPublic PoC

Published: 31 March 2026

Published

31 March 2026

Modified

13 April 2026

KEV Added

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Patch

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CVSS Score 8.1 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS Score 0.0004 11.4th percentile

Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-32726 is a high-severity Incorrect Authorization (CWE-863) vulnerability in Scitokens Scitokens Cpp Library. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 11.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 AC-25 (Reference Monitor) and AC-3 (Access Enforcement).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

AC-3 Access Enforcement good match

prevent

Requires enforcement of approved authorizations for access to resources, directly addressing the authorization bypass from flawed path-based scope validation using simple prefix matching without segment boundaries.

SI-2 Flaw Remediation good match

prevent

Mandates identification, reporting, and correction of system flaws like the scitokens-cpp authorization vulnerability, enabling upgrade to the patched version 1.4.1.

AC-25 Reference Monitor good match

prevent

Implements a tamperproof reference monitor to enforce access control policies, mitigating the vulnerable library enforcer's failure to require path-segment boundaries in scope checks.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1068 Exploitation for Privilege Escalation Privilege Escalation

Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.

attack.mitre.org →

Why these techniques?

Authorization bypass in public-facing SciTokens enforcement enables exploitation of exposed applications (T1190) and allows low-privileged token holders to access unauthorized sibling paths/resources, constituting privilege escalation (T1068).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

NVD Description

SciTokens C++ is a minimal library for creating and using SciTokens from C or C++. Prior to version 1.4.1, scitokens-cpp is vulnerable to an authorization bypass in path-based scope validation. The enforcer used a simple string-prefix comparison when checking whether…

a requested resource path was covered by a token's authorized scope path. Because the check did not require a path-segment boundary, a token scoped to one path could incorrectly authorize access to sibling paths that merely started with the same prefix. This issue has been patched in version 1.4.1.

Deeper analysisAI

CVE-2026-32726 is an authorization bypass vulnerability in the SciTokens C++ library (scitokens-cpp), a minimal implementation for creating and using SciTokens from C or C++. In versions prior to 1.4.1, the library's enforcer performs path-based scope validation using a simple string-prefix comparison without enforcing path-segment boundaries. This allows a token authorized for a specific path to incorrectly grant access to sibling paths that share the same prefix, as the check does not require delimiter separation. The issue is classified under CWE-863 (Incorrect Authorization) with a CVSS v3.1 base score of 8.1 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N).

An attacker with low privileges (PR:L) can exploit this over the network (AV:N) with low complexity and no user interaction required. By obtaining a valid SciTokens token scoped to a path prefix, such as "/data/special/", the attacker could access unauthorized sibling resources like "/data/specialist/" or "/data/specialops/". Successful exploitation enables high confidentiality and integrity impacts (C:H/I:H), potentially allowing unauthorized data access or modification within the affected SciTokens-protected services, while availability remains unaffected (A:N).

The vulnerability has been patched in scitokens-cpp version 1.4.1, as detailed in the GitHub security advisory (GHSA-q5fm-fgvx-32jq) and the fixing commit (decfe2f00cb9cabbf1e17a3bb2cd4ea1bbbd8a73). Security practitioners should upgrade to version 1.4.1 or later to mitigate the issue, and review token scopes in deployments using earlier versions for potential over-permissions.