Cyber Resilience

CVE-2026-36609

Crypto Weakness

Crypto Weakness
Published
03 June 2026
Modified
22 July 2026
CVSS Score v3.1 7.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0017 6th percentile
Risk Priority 54 floored blend · peak EPSS

Summary

CVE-2026-36609 is a high-severity Use of a Broken or Risky Cryptographic Algorithm (CWE-327) vulnerability. Its CVSS base score is 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 6th 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 IA-5 (Authenticator Management) and SC-12 (Cryptographic Key Establishment and Management) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A04:2025 Cryptographic Failures

EU & UK References

Vulnerability Data

Mercusys AC12G (EU) V1 router with firmware AC12G(EU)_V1_200909 uses a static authentication nonce that does not change between requests from the same source IP. Combined with the predictable XOR-based password encoding (securityEncode function), this allows an attacker to reverse captured…

more

authentication tokens to recover the plaintext password.

CWE(s)
CWE-327CWE-341

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 →
T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
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 →
T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
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 →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-49259Shared CWE-327, CWE-341
CVE-2026-38968Shared CWE-341
CVE-2025-48461Shared CWE-341
CVE-2026-42365Shared CWE-341
CVE-2025-42925Shared CWE-341
CVE-2025-40780Shared CWE-341
CVE-2024-47187Shared CWE-327
CVE-2024-47188Shared CWE-327
CVE-2023-40696Shared CWE-327
CVE-2024-4765Shared CWE-327

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 6 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.6.1
  • V6.5.1
  • V6.5.3
  • V6.5.5

Mitigating Controls (NIST 800-53 r5) AI

SC-13 Cryptographic Protection good match

SC-13 requires selection and implementation of specific cryptography types, directly stopping use of broken algorithms.

IA-5 Authenticator Management good match

Authenticator management requires generation and distribution of values that cannot be derived from observable state.

SC-12 Cryptographic Key Establishment and Management good match

Cryptographic key establishment mandates use of unpredictable, non-observable values for keys and nonces.

SC-23 Session Authenticity good match

Session authenticity protection requires session identifiers or tokens that resist prediction from network or timing observations.

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.PS-06 mostly match
prevents

Secure SDLC practices directly require cryptographically secure random values instead of observable state such as time or PID.

PR.DS-01 partial match
prevents

PR.DS-01 promotes encryption for data-at-rest but never requires strong algorithms, leaving CWE-327 fully possible; the weakness is also far broader than data-at-rest so one narrow control removes none of its total risk.

PR.PS-01 partial match
prevents

Hardened configuration baselines can enforce use of cryptographically secure RNG sources and disable predictable state-based mechanisms.

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

Mandating approved algorithms, cipher strength and usage standards directly stops the selection of broken or weak cryptographic primitives that attackers can exploit.

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

Security testing can detect predictability issues but does not prevent them by itself.

A.5.31 Legal, statutory, regulatory and contractual requirements partial match
prevents

The explicit call-out of cryptography-related legal constraints (import/export, key escrow, digital-signature validity) reduces the likelihood that an organization will adopt broken or non-compliant cryptographic algorithms that violate those rules.

A.5.6 Contact with special interest groups partial match
prevents

Access to current specialist guidance and early vulnerability alerts enables timely replacement of broken or risky cryptographic algorithms with stronger alternatives.

A.8.25 Secure development life cycle partial match
prevents

SDLC requirements encourage secure design but do not directly mandate removal of predictable state.

A.8.28 Secure coding partial match
prevents

Secure coding practices explicitly forbid use of predictable state (time, PID, counters) for secrets or tokens.

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-248524 OL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. prevents CWE-327
Windows 10 (1 rule)
  • V-220937 The system must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows 11 (1 rule)
  • V-253461 The system must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows Server 2016 (1 rule)
  • V-225053 Windows Server 2016 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows Server 2019 (1 rule)
  • V-205654 Windows Server 2019 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327
Windows Server 2022 (1 rule)
  • V-254474 Windows Server 2022 must be configured to prevent the storage of the LAN Manager hash of passwords. prevents CWE-327

References