CVE-2026-54893
Raw vector
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-54893 is a low-severity Improper Encoding or Escaping of Output (CWE-116) vulnerability in Erlef (inferred from references). Its CVSS base score is 2.1 (Low).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-41876
Vulnerability Data
URL path injection in the Microsoft Graph adapter of Swoosh. Swoosh.Adapters.MsGraph builds its Microsoft Graph API request URL by interpolating the sender's email address into the URL path (/users/{from}/sendMail) without percent-encoding or validation. In applications that derive the from address…
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from untrusted or user-influenced input (for example a relay, a contact form, or a "send as" feature), an attacker can place URL-special characters such as /, ?, or # in the local part of the address to escape the intended path segment and rewrite the path and query string of the request. Because the same authenticated POST is sent with the application's Microsoft Graph bearer token, the attacker can redirect it to other Graph endpoints within the token's scopes and control the request's query string. Applications that always use a fixed, trusted from address are not affected. This issue affects swoosh from 1.12.0 before 1.26.3.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
URL path injection allows an attacker to redirect authenticated Microsoft Graph API calls to arbitrary endpoints within token scope when untrusted sender addresses are used, directly enabling exploitation of a public-facing application.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
Mitigating Controls (NIST 800-53 r5) AI
Directly requires validation and sanitization of untrusted email input before it is interpolated into the Graph API URL path, blocking the path-injection vector.
Limits the Graph bearer token to the minimum scopes needed for sendMail, reducing the attacker’s ability to reach other endpoints even if path rewriting succeeds.
Enforces information-flow rules that prevent untrusted data from altering the structure of an outbound authenticated request to an external API.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require proper output encoding to prevent injection and message malformation.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure coding standards explicitly require correct output encoding and escaping to preserve message structure.
Security testing can detect missing or incorrect encoding but does not itself implement the control.
Secure development life cycle mandates output encoding/escaping practices that directly prevent improper encoding.
Application security requirements include explicit rules for safe output handling and encoding.
Secure architecture principles reduce the likelihood of missing encoding but do not prescribe the actual technique.