CVE-2026-25534: Spinnaker clouddriver and orca URL validation bypass via underscores in hostnames

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. 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 0.4%, percentile 35: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 35% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes io.spinnaker.clouddriver:clouddriver-artifacts (Maven) >= 2025.3.0, < 2025.3.1, fixed in 2025.3.1; io.spinnaker.clouddriver:clouddriver-artifacts (Maven) >= 2025.4.0, < 2025.4.1, fixed in 2025.4.1; io.spinnaker.orca:orca-core (Maven) >= 2025.3.0, < 2025.3.1, fixed in 2025.3.1; io.spinnaker.orca:orca-core (Maven) >= 2025.4.0, < 2025.4.1, fixed in 2025.4.1. Check your lockfile, including transitive dependencies.

What it is

Impact Spinnaker updated URL Validation logic on user input to provide sanitation on user inputted URLs for clouddriver. However, they missed that Java URL objects do not correctly handle underscores on parsing. This led to a bypass of the previous CVE (CVE-2025-61916) through the use of carefully crafted URLs. Note, Spinnaker found this not just in that CVE, but in the existing URL validations in Orca fromUrl expression handling. This CVE impacts BOTH artifacts as a result. Patches This has been merged and will be available in versions 2025.4.1, 2025.3.1, 2025.2.4 and 2026.0.0. Workarounds You can disable the various artifacts on this system to work around these limits.

From the GitHub advisory

Impact Spinnaker updated URL Validation logic on user input to provide sanitation on user inputted URLs for clouddriver. However, they missed that Java URL objects do not correctly handle underscores on parsing. This led to a bypass of the previous CVE (CVE-2025-61916) through the use of carefully crafted URLs. Note, Spinnaker found this not just in that CVE, but in the existing URL validations in Orca fromUrl expression handling. This CVE impacts BOTH artifacts as a result.

Patches This has been merged and will be available in versions 2025.4.1, 2025.3.1, 2025.2.4 and 2026.0.0.

Workarounds You can disable the various artifacts on this system to work around these limits.

Weakness type: CWE-918.

Product: io.spinnaker.clouddriver:clouddriver-artifacts (Maven) · Assigned by: GitHub_M · Published: 2026-03-17

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• Scope: changed (can affect other components)

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 no, technical impact partial.
• FIRST EPSS (model of 2026-10-21): 0.42% probability of exploitation activity in the next 30 days; percentile 35.

Timeline

• 2026-03-16 — GitHub-reviewed advisory GHSA-8r8j-gfhg-fw38 published (critical)
• 2026-03-17 — CVE record last updated
• 2026-03-17 — CVE record published by GitHub_M

Sources and references

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

Vulnerability records

1. GitHub Advisory GHSA-8r8j-gfhg-fw38 github.com
2. CVE.org record CVE-2026-25534 cve.org
3. NVD entry CVE-2026-25534 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com
3. github.com github.com

Critical Maven advisories · Today’s Security Digest