VulnerabilityPublished 27 Mar 2026

CVE-2026-33954: Kovah LinkAce · Improper Authorization

Affects Kovah LinkAceSource CVE Database V5

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Not known to be exploited · CVSS 6.5 Medium : upgrade to 2.5.3 when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

6.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 25% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.5.3

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 27 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade LinkAce and kovah/LinkAce to 2.5.3.

Affected software

Product	Affected	Fixed in
KovahLinkAce	Affected <2.5.3	Fixed in 2.5.3
GitHubkovah/LinkAce`pkg:github/kovah/LinkAce`Other threats	Affected <2.5.3	Fixed in 2.5.3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The most effective mitigation is to upgrade LinkAce to version 2.5.3 or later, where the vulnerability is patched. Until an upgrade is possible, organizations should restrict access to the LinkAce web interface to trusted users only and consider limiting user permissions to minimize exposure. Administrators can audit existing private notes and assess their sensitivity, removing or relocating highly sensitive information if needed. Additionally, monitoring access logs for unusual patterns of note access may help detect exploitation attempts. Implementing network-level controls such as VPNs or IP whitelisting can reduce exposure to unauthorized users. Finally, educating users about the risk of storing sensitive information in private notes until the patch is applied is advisable.

Description

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 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.

Impact

The primary impact of this vulnerability is unauthorized disclosure of private notes, which may contain sensitive or confidential information. Organizations using LinkAce for internal knowledge management or link archiving could inadvertently expose private annotations to other authenticated users, potentially leading to information leakage within the organization. This could undermine trust in the platform, violate privacy policies, or expose strategic or proprietary data. Since the vulnerability does not affect data integrity or availability, the risk is limited to confidentiality breaches. However, in environments where LinkAce is used by multiple users with varying access levels, the impact could be significant, especially if private notes contain sensitive operational or business intelligence. The medium CVSS score reflects the moderate risk posed by this issue.

Summary

CVE-2026-33954 is a medium-severity improper authorization vulnerability (CWE-285) affecting Kovah's LinkAce, a self-hosted web link archiving tool. In versions prior to 2.5.3, the web interface improperly handles visibility controls for private notes attached to links. While the API correctly restricts access to private notes, the web link detail page fails to enforce these restrictions, allowing any authenticated user who can view another user's internal or public link to also view that user's private notes attached to the link. This discrepancy between API and web interface authorization checks leads to unauthorized disclosure of sensitive information. The vulnerability requires authentication but no additional user interaction, and exploitation can be performed remotely over the network. The flaw impacts confidentiality but does not affect integrity or availability. The issue was publicly disclosed on March 27, 2026, and fixed in LinkAce version 2.5.3. No known exploits are reported in the wild as of now.

CWE-285Improper Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that you perform access control checks related to your business logic. These checks may be different than the access control checks that you apply to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
Attack patterns
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Directory Indexing (opens in a new tab)
Subverting Environment Variable Values (opens in a new tab)
Using Malicious Files (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/Kovah/LinkAce/security/advisories/GHSA-88h3-cq25-vw8q (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Mar 2026, 21:53 UTC

WeaknessesCWE-285

Technical details

References

Community reviews

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