Security Digest · Vulnerability record

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

Apache Druid’s Kerberos authenticator uses a weak fallback secret when the druid.auth.authenticator.kerberos.cookieSignatureSecret configuration is not explicitly set.

CVSS 9.8 Critical EPSS 0.6% · p49

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

  • 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.

From the GitHub advisory

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.

Weakness type: CWE-338.

Product: org.apache.druid:druid (Maven) · Assigned by: apache · Published: 2025-11-26

Affected and fixed versions

EcosystemPackageVulnerableFirst fixed
Mavenorg.apache.druid:druid< 35.0.035.0.0
VendorProductAffected versions (per CVE record)
Apache Software FoundationApache Druid<= 34.0.0

Severity scores

Scored byCVSSScoreVector
CISA-ADP3.19.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub3.19.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
  • Attack vector: network (remotely reachable)
  • Attack complexity: low
  • Privileges required: none (no login)
  • User interaction: none
  • Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

  • 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.

Timeline

  • — CVE record published by apache
  • — GitHub-reviewed advisory GHSA-w88f-4875-99c8 published (critical)
  • — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

  1. lists.apache.org lists.apache.org

Vulnerability records

  1. GitHub Advisory GHSA-w88f-4875-99c8 github.com
  2. CVE.org record CVE-2025-59390 cve.org
  3. NVD entry CVE-2025-59390 nvd.nist.gov

Other references from the CVE record and advisory

  1. openwall.com openwall.com
  2. github.com github.com

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