---
title: "CVE-2025-59390: Apache Druid’s Kerberos authenticator uses a weak fallback secret"
url: https://erroneo.us/security/cve/CVE-2025-59390/
description: "CVE-2025-59390 (org.apache.druid:druid (Maven)): Apache Druid’s Kerberos authenticator uses a weak fallback secret when the…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-11-26
date_modified: 2025-12-11
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-59390"
kev: false
cvss: 9.8
epss: 0.00611
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-59390: Apache Druid’s Kerberos authenticator uses a weak fallback secret

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.6% , percentile 49: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 49% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes org.apache.druid:druid (Maven) < 35.0.0, fixed in 35.0.0 . Check your lockfile, including transitive dependencies.

## What it is

Apache Druid’s Kerberos authenticator uses a weak fallback secret when the druid.auth.authenticator.kerberos.cookieSignatureSecret configuration is not explicitly set. In this case, the secret is generated using ThreadLocalRandom, which is not a crypto-graphically secure random number generator. This may allow an attacker to predict or brute force the secret used to sign authentication cookies, potentially enabling token forgery or authentication bypass. Additionally, each process generates its own fallback secret, resulting in inconsistent secrets across nodes. This causes authentication failures in distributed or multi-broker deployments, effectively leading to a incorrectly configured clusters. Users are advised to configure a strong druid.auth.authenticator.kerberos.cookieSignatureSecret This issue affects Apache Druid: through 34.0.0. Users are recommended to upgrade to version 35.0.0, which fixes the issue making it mandatory to set druid.auth.authenticator.kerberos.cookieSignatureSecret when using the Kerberos authenticator. Services will fail to come up if the secret is not set.

## Affected packages

- Maven `org.apache.druid:druid` < 35.0.0 → fixed: 35.0.0

## Affected products (CVE record)

- Apache Software Foundation Apache Druid: <= 34.0.0

## Severity

- CISA-ADP CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.61% probability of exploitation activity in the next 30 days; percentile 49.

## Sources

- [lists.apache.org](https://lists.apache.org/thread/jwjltllnntgj1sb9wzsjmvwm9f8rlhg8)
- [GitHub Advisory GHSA-w88f-4875-99c8](https://github.com/advisories/GHSA-w88f-4875-99c8)
- [CVE.org record CVE-2025-59390](https://www.cve.org/CVERecord?id=CVE-2025-59390)
- [NVD entry CVE-2025-59390](https://nvd.nist.gov/vuln/detail/CVE-2025-59390)
- [openwall.com](http://www.openwall.com/lists/oss-security/2025/11/26/1)
- [github.com](https://github.com/apache/druid/pull/18368)

---
Source page: https://erroneo.us/security/cve/CVE-2025-59390/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt