VulnerabilityPublished 13 Jul 2026

CVE-2026-52819: Kimai · Teamlead authorization bypass in GET /api/timesheets allows reading other users' timesheet records without being teamlead of the target

Affects kimai/kimaiSource GCVE Database

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Not known to be exploited · CVSS 6.3 Medium : upgrade to 2.57.0 when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 4.0 base score

6.3Medium

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.57.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Jul 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 kimai/kimai to 2.57.0.

Affected software

Product	Affected	Fixed in
Packagistkimai/kimai	Affected <2.57.0	Fixed in 2.57.0

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AI-suggested

The disclosed solution involves enforcing the access_user permission on the GET /api/timesheets list endpoint, which verifies that the requesting user is authorized to view each requested user's timesheet data. If you cannot patch yet, restrict ROLE_TEAMLEAD users' permissions or avoid using the vulnerable list endpoint with user parameters to prevent unauthorized data access.

Description

Kimai versions prior to 2.57.0 contain an authorization bypass vulnerability in the GET /api/timesheets endpoint. A user with the ROLE_TEAMLEAD and the view_other_timesheet permission can retrieve timesheet records of other users without being the teamlead of the target user's team. This bypass occurs because the list endpoint does not enforce the teamlead check that the per-record endpoint enforces. As a result, sensitive financial data such as rate and internalRate, along with personal activity details, can be disclosed to unauthorized teamlead users.

Impact

A user with the ROLE_TEAMLEAD role and the view_other_timesheet permission can bypass intended authorization controls to access other users' timesheet records without being their teamlead. This results in unauthorized disclosure of sensitive financial information (rate, internalRate) and personally identifiable information related to user activities (descriptions, timestamps, durations, billable status, tags, and project/customer associations). This exposure can lead to privacy violations and potential misuse of financial data within organizations using Kimai.

Summary

The vulnerability arises from an authorization mismatch between the per-record timesheet access control and the list endpoint in Kimai. While the per-record endpoint correctly verifies that a requester with view_other_timesheet permission is the teamlead of the target user's team, the list endpoint (GET /api/timesheets?user=<id>) fails to enforce this check. Instead, it only filters projects/customers by team membership, allowing any teamlead with the permission to enumerate timesheets of users they are not teamlead of, provided the timesheets belong to projects with no team scoping or shared teams where the requester is a member but not a lead. This leads to unauthorized disclosure of timesheet records including financial rates and personal activity data. The issue affects Kimai versions before 2.57.0. The fix involves adding an access_user permission check to the list endpoint to ensure the requester is authorized to view each requested user's data.

CWE-863Incorrect Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #17OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
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 access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied 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)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 Jul 2026, 09:45 UTC

WeaknessesCWE-863

Technical details

References

Community reviews

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