Cyber Resilience

CVE-2026-47085

Published
16 July 2026
Modified
17 July 2026
CVSS Score v3.1 4.0
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N
EPSS Score 0.0020 10th percentile
Risk Priority 32 floored blend · peak EPSS

Summary

CVE-2026-47085 is a medium-severity Generation of Predictable Numbers or Identifiers (CWE-340) vulnerability in Cyrusimap (inferred from references). Its CVSS base score is 4.0 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Web Cookies (T1606.001); ranked at the 10th 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 SA-11 (Developer Testing and Evaluation) 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

An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2. URLAUTH token forgery can occur via a missing mboxkey. If an attacker knew a folder name on the victim's account for which the victim had never issued an auth…

more

URL, they could forge a working URLAUTH token by computing an HMAC-SHA1 value with a predictable key, giving them read access to the mailbox. (URLAUTH is an obscure feature, meaning that the odds of any user actually being susceptible to this attack are very low. Perhaps no public clients use URLAUTH.)

CWE(s)
CWE-340

Related Threats

MITRE ATT&CK Enterprise Techniques

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 →
T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
attack.mitre.org →
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 →
T1558 Steal or Forge Kerberos Tickets Credential Access
Adversaries may attempt to subvert Kerberos authentication by stealing or forging Kerberos tickets to enable [Pass the Ticket](https://attack.
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-2025-3449Shared CWE-340
CVE-2025-62294Shared CWE-340
CVE-2025-13044Shared CWE-340
CVE-2025-69286Shared CWE-340
CVE-2025-59452Shared CWE-340
CVE-2025-58424Shared CWE-340
CVE-2026-9219Shared CWE-340
CVE-2024-28957Shared CWE-340
CVE-2024-10603Shared CWE-340
CVE-2024-52299Shared CWE-340

Affected Assets

Cyrusimap
—
inferred from references and description; NVD did not file a CPE for this CVE

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 · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V11.3.4

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover predictable number generation through targeted analysis or fuzzing of identifier creation routines.

SC-12 Cryptographic Key Establishment and Management good match

Cryptographic key establishment and management mandates proper entropy and randomness during generation, directly stopping predictable identifiers at the source.

IA-5 Authenticator Management partial match

Authenticator management requires secure initial distribution and handling of authenticators, structurally preventing predictable values from being usable.

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 strong RNG for identifiers and tokens, covering most of this weakness while the control addresses many additional development issues.

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

Cryptographic controls require use of approved, sufficiently random algorithms and key-generation methods, directly mitigating predictable number/identifier weaknesses.

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

Security testing in development can detect predictable identifiers through static/dynamic analysis and fuzzing, reducing residual risk.

A.8.25 Secure development life cycle partial match
prevents

A secure SDLC incorporates threat modelling and secure-design reviews that flag predictable identifier generation early in the lifecycle.

A.8.28 Secure coding partial match
prevents

Secure-coding standards explicitly forbid predictable random functions and mandate cryptographically secure RNGs, preventing the weakness at the source.

A.8.5 Secure authentication partial match
prevents

Secure authentication mechanisms depend on unpredictable session tokens, nonces and challenges; eliminating predictable identifiers strengthens authentication integrity.

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 (2 rules)
  • 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-340
  • V-248600 OL 8 must have the packages required to use the hardware random number generator entropy gatherer service. prevents CWE-340
RHEL 7 (1 rule)
  • V-204497 The Red Hat Enterprise Linux operating system 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-340
RHEL 8 (1 rule)
  • V-244527 RHEL 8 must have the packages required to use the hardware random number generator entropy gatherer service. prevents CWE-340

References