Cyber Resilience

CVE-2026-33954

Access Control in Linkace ≤ 2.5.3

Public PoCAccess Control
Published
27 March 2026
Modified
31 March 2026
Patch / advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0032 24th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-33954 is a medium-severity Improper Authorization (CWE-285) vulnerability in Linkace Linkace. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Information Repositories (T1213); ranked at the 24th 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-3 (Access Enforcement) 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

Vulnerability Data

LinkAce is a self-hosted archive to collect website links. In versions prior to 2.5.3, a private note attached to a non-private link can be disclosed to a different authenticated user via the web interface. The API appears to correctly enforce…

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note visibility, but the web link detail page renders notes without applying equivalent visibility filtering. As a result, an authenticated user who is allowed to view another user's `internal` or `public` link can read that user's `private` notes attached to the link. Version 2.5.3 patches the issue.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1213 Data from Information Repositories Collection
Adversaries may leverage information repositories to mine valuable information.
Why these techniques?

Vulnerability enables unauthorized access to private notes stored in the LinkAce link/note repository via the web UI due to missing authorization checks (CWE-285).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-30954Same product: Linkace Linkace
CVE-2025-62720Same product: Linkace Linkace
CVE-2025-62721Same product: Linkace Linkace
CVE-2025-62722Same product: Linkace Linkace
CVE-2025-59424Same product: Linkace Linkace
CVE-2026-30953Same product: Linkace Linkace
CVE-2024-56508Same product: Linkace Linkace
CVE-2025-53838Same product: Linkace Linkace
CVE-2024-56507Same product: Linkace Linkace
CVE-2026-27458Same product: Linkace Linkace

Affected Assets

linkace
linkace
≤ 2.5.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • AC-4 Information Flow Enforcement
  • AC-6 Least Privilege
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces authorization rules so that private notes are never rendered to users lacking the required visibility privilege on the web link-detail page.

prevent

Controls information flows between subjects, ensuring private notes attached to a link are not disclosed to another authenticated user even when the link itself is viewable.

prevent

Limits each user to the minimum set of privileges needed, preventing access to another user's private notes regardless of link visibility.

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-05 mostly match
prevents

PR.AA-05 mostly prevents CWE-285 via enforced policy, reviews, and least-privilege authorization decisions, yet CWE-285 remains only partially prevented because code-level check omissions or errors can still occur outside that single control.

PR.PS-06 mostly match
prevents

Secure SDLC practices catch and eliminate most authorization defects before release, yet a single broad outcome cannot address every design, role, and runtime facet of CWE-285.

PR.AA-01 partial match
prevents

PR.AA-01 supplies managed identities and access-request workflows that can support downstream authorization decisions, yet does nothing to enforce or verify authorization checks inside a product, leaving CWE-285 fully unaddressed by this control alone.

PR.IR-01 partial match
prevents

Network segmentation/zero-trust limits external reachability (partial prevention of exploitation) but leaves application-level authorization logic untouched, so the CWE remains fully introducible and only one facet of its risk is addressed.

PR.PS-05 none match
prevents

PR.PS-05 blocks unauthorized binaries/DNS while CWE-285 is an in-product authorization-check defect, so the control neither prevents the weakness nor removes any of its risk.

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.

prevents

Granular, policy-driven assignment of permissions and dynamic enforcement of those permissions prevent the incorrect or missing authorization decisions that lead to improper authorization flaws.

prevents

By requiring documented authorization rules and periodic policy reviews, the control makes it less likely that authorization decisions will be omitted or implemented inconsistently across applications.

prevents

Mapping access rights to information classification and business requirements forces correct enforcement of authorization decisions, blocking the incorrect authorization weakness at the policy and implementation stage.

detects

Independent reviewers evaluate whether authorization logic matches policy, thereby reducing the window in which incorrect or missing authorization checks remain in production.

detects

By requiring managers to verify that authorization decisions match policy and to remediate deviations, the control limits the persistence of incorrect or missing authorization checks.

prevents

Requiring authorization processes and privilege assignments to be specified during project initiation prevents downstream components from receiving overly broad or incorrect rights that would allow unauthorized actions.

References