How severe is CVE-2026-52827?

No CVSS score has been assigned to CVE-2026-52827 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-52827?

CVE-2026-52827 affects the following packages: kimai/kimai (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2026-52827?

Update kimai/kimai to 2.59.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-52827 is resolved across your whole dependency graph.

How do I detect CVE-2026-52827 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for kimai/kimai, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-52827 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-52827 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-52827 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-52827?

CVE-2026-52827 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 46th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-52827?

CVE-2026-52827 is classified as Improper Authentication (CWE-287). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-52827 published, and has it been updated?

CVE-2026-52827 was published on September 15, 2026 and was last updated on October 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

CVE-2026-52827 — kimai

Fix: kimai/kimai@87c8527

CVE-2026-52827 is a Improper Authentication vulnerability in kimai/kimai. A fix is available for kimai/kimai — see the affected versions and patch details below.

Kimai: Two-factor authentication bypass on the Kimai API

Also known asGHSA-v8hx-4vx8-wc96

Published

Sep 15, 2026

Updated

Oct 2, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-52827.

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs46th percentile — riskier than 46% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐘kimai/kimai

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Two-factor authentication (TOTP) can be fully bypassed for the REST API. The KIMAI_SESSION cookie returned in the response to the login request; issued after only the password is verified, before the TOTP step; is already accepted as authenticated by every /api/* endpoint.

So after submitting just the password, the web UI correctly holds the browser at the TOTP screen (/en/auth/2fa), but the cookie from that same login response can be replayed against the API to act as the user without ever entering the second factor. This affects any account with 2FA enabled and requires only the account password.

Details

Affected Component

The API firewall / authorization.

config/packages/security.yaml guards the API with { path: '^/api', roles: IS_AUTHENTICATED }. During 2FA the session carries a Scheb TwoFactorToken, which satisfies IS_AUTHENTICATED (it is a real, non-anonymous token). App\API\Authentication\ApiRequestMatcher returns !$request->hasPreviousSession(), so a request that carries the login session skips the stateless API firewall and is served by the main session firewall; Scheb's TwoFactorAccessDecider::isAccessible() then evaluates IS_AUTHENTICATED to true for ^/api and lets it through, and App\Voter\ApiVoter grants API to any token whose user is a User. Web routes are not affected because they require concrete roles (e.g. ROLE_USER) that a TwoFactorToken does not hold.

PoC

A PoC was provided, but removed for security reasons.

Impact

Two-factor authentication provides no protection for the REST API. If an attacker obtains a user's password (phishing, credential stuffing, reuse, breach); exactly the threat 2FA is meant to defend against; they get full authenticated API access as that user without the second factor. The whole exploit is a single cookie taken from the login response; no API token, Bearer header or CSRF token is required.

Solution

The /api/ firewall now uses IS_AUTHENTICATED_REMEMBERED which is only assigned after 2FA. The historically used IS_AUTHENTICATED flag is applied immediately after login and before 2FA happened.
The APIVoter checks both $token instanceof TwoFactorTokenInterface and isGranted('IS_AUTHENTICATED_2FA_IN_PROGRESS', $user) to make sure that the user is not currently in the 2FA step.
Regression tests were added to prevent future escalation of the same issue.

See https://www.kimai.org/en/security/ghsa-v8hx-4vx8-wc96 for more information.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`kimai/kimai`	all versions	2.59.0`composer require kimai/kimai:^2.59.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for kimai/kimai, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update kimai/kimai to 2.59.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-52827 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

### Summary Two-factor authentication (TOTP) can be fully bypassed for the REST API. The `KIMAI_SESSION` cookie returned in the response to the login request; issued after only the password is verified, before the TOTP step; is already accepted as authenticated by every `/api/*` endpoint. So after submitting just the password, the web UI correctly holds the browser at the TOTP screen (`/en/auth/2fa`), but the cookie from that same login response can be replayed against the API to act as the user without ever entering the second factor. This affects any account with 2FA enabled and requires on

O3 Security · Impact-Aware SCA

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