Cyber Resilience

CVE-2026-63089

Public PoC
Published
16 July 2026
Modified
18 July 2026
CVSS Score v4 9.0
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/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:X
EPSS Score 0.0024 15th percentile
Risk Priority 43 floored blend · peak EPSS

Summary

CVE-2026-63089 is a critical-severity PRNG (CWE-338) vulnerability. Its CVSS base score is 9.0 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 15th 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 map to AC-12 (Session Termination) and SC-13 (Cryptographic Protection) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A04:2025 Cryptographic FailuresA07:2025 Authentication Failures

EU & UK References

Vulnerability Data

WireGuard Easy through 15.3.0, fixed in commit 66b292b, contains a cryptographically weak one-time link token generation vulnerability that allows unauthenticated network attackers to recover WireGuard peer credentials by brute-forcing a keyspace of at most 1000 candidate tokens per client ID,…

more

as the token is computed using CRC32 over a random value constrained to 0-999. Attackers can enumerate candidate tokens against the unauthenticated /cnf/:oneTimeLink route, which lacks rate limiting and does not validate token expiration, to obtain a peer's PrivateKey and PresharedKey and impersonate that peer on the VPN network.

CWE(s)
CWE-338CWE-613

Related Threats

MITRE ATT&CK Enterprise Techniques

T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
attack.mitre.org →
T1550 Use Alternate Authentication Material Lateral Movement
Adversaries may use alternate authentication material, such as password hashes, Kerberos tickets, and application access tokens, in order to move laterally within an environment and bypass normal system access controls.
attack.mitre.org →
T1550.004 Web Session Cookie Lateral Movement
Adversaries can use stolen session cookies to authenticate to web applications and services.
attack.mitre.org →
T1563 Remote Service Session Hijacking Lateral Movement
Adversaries may take control of preexisting sessions with remote services to move laterally in an environment.
attack.mitre.org →
T1606 Forge Web Credentials Credential Access
Adversaries may forge credential materials that can be used to gain access to web applications or Internet services.
attack.mitre.org →
T1606.001 Web Cookies Credential Access
Adversaries may forge web cookies that can be used to gain access to web applications or Internet services.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-46344Shared CWE-613
CVE-2023-5889Shared CWE-613
CVE-2025-53896Shared CWE-613
CVE-2025-24896Shared CWE-613
CVE-2026-27647Shared CWE-613
CVE-2026-26342Shared CWE-613
CVE-2024-29070Shared CWE-613
CVE-2026-40934Shared CWE-613
CVE-2026-39924Shared CWE-613
CVE-2024-27779Shared CWE-613

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V7.2.3
  • V11.5.1

Mitigating Controls (NIST 800-53 r5) AI

AC-12 Session Termination good match

AC-12 directly requires automatic session termination after a defined period, structurally preventing reuse of expired session identifiers.

SC-13 Cryptographic Protection good match

Requiring specific approved cryptography for protection directly mandates use of strong PRNGs instead of weak ones.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles applied during design and development include selection of cryptographically strong random number generation.

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.

PR.AA-01 mostly match
prevents

Credential lifecycle management directly includes enforcing session expiration to prevent reuse.

PR.AA-05 mostly match
prevents

Authorization policy enforcement and review covers terminating stale sessions to limit access scope.

PR.PS-06 mostly match
prevents

Secure SDLC practices explicitly require cryptographically strong RNG selection and usage in security contexts.

PR.AA-03 partial match
prevents

Authentication mechanisms can incorporate session timeout checks but do not inherently address expiration policy.

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.

A.8.24 Use of cryptography mostly match
prevents

Mandates use of approved cryptographic controls, directly requiring cryptographically strong RNGs.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect use of weak random number generators.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC processes should catch weak PRNG usage during design and code review.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify cryptographically strong random number generation.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure engineering principles include selection of appropriate cryptographic primitives.

A.8.28 Secure coding partial match
prevents

Secure coding standards prohibit use of weak PRNGs in security contexts.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248563 The OL 8 SSH server must be configured to use strong entropy. prevents CWE-338
RHEL 8 (1 rule)
  • V-230253 RHEL 8 must ensure the SSH server uses strong entropy. prevents CWE-338
Ubuntu 22.04 (1 rule)
  • V-260650 Ubuntu 22.04 LTS must implement NIST FIPS-validated cryptography to protect classified information and for the following: To provision digital signatures, to generate cryptographic hashes, and to protect unclassified information requiring confidentiality and cryptographic protection in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. prevents CWE-338

References