CVE-2026-75757
Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/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:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-75757 is a high-severity Reliance on Cookies without Validation and Integrity Checking (CWE-565) vulnerability in Erlef (inferred from references). Its CVSS base score is 8.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Steal Web Session Cookie (T1539); ranked at the 23th 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 AC-3 (Access Enforcement) and SC-23 (Session Authenticity) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-68324
Vulnerability Data
Reliance on Cookies without Validation and Integrity Checking vulnerability in ash-project ash_admin lets an attacker who controls a sibling subdomain rebind an admin's session to a different actor, tenant, or authorization mode. AshAdmin's client JavaScript read its state cookies (tenant,…
more
actor_resource, actor_primary_key, actor_action, actor_domain, actor_authorizing, actor_paused) by matching the cookie name with an unanchored regular expression (new RegExp(name + "=([^;]+)")) against the whole document.cookie. Any cookie whose name merely ends with the requested name therefore matches, and whichever is serialized first wins. Because cookies are shared across a registrable domain, a compromised sibling subdomain can set a shadowing cookie (for example xactor_authorizing) with Domain=.example.com that flows unvalidated into the admin's LiveSocket connect params. The fix matches cookie names by exact equality. This issue affects ash_admin: from 0.9.1 before 1.3.1.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Access Enforcement requires authorizations to be enforced by the system rather than by trusting client-supplied cookie values.
Session Authenticity directly requires protecting the integrity and authenticity of session tokens such as cookies, eliminating blind reliance on them.
Transmission Confidentiality and Integrity mandates cryptographic or equivalent protection for data in transit, which covers cookie values exchanged over HTTP.
Software, Firmware, and Information Integrity can detect unauthorized modification of cookie-based data after the fact via integrity verification.
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.
Strong authentication mechanisms reduce reliance on unvalidated cookies for identity and access decisions.
Cookies commonly carry identity assertions; requiring their protection, conveyance, and verification directly eliminates the weakness.
Enforcing access policy and least privilege limits damage from cookie misuse but does not address cookie validation itself.
Integrity protections for data-at-rest can apply to cookie stores but do not cover validation during use.
Cryptographic integrity for data-in-transit directly mitigates tampering of cookies sent over the network.
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.
Application security requirements can mandate cookie validation, integrity protection, and server-side session handling.
Secure coding practices directly eliminate reliance on unvalidated cookies by requiring proper integrity checks and server-side verification.
Security testing can detect cookie-validation flaws but does not itself implement the required controls.
Secure authentication mechanisms can enforce server-side validation and integrity checks that prevent reliance on untrusted cookies.