CVE-2026-42571: Pelican Web UI Affected by a Privilege Escalation Attack

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 33: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 33% 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 github.com/pelicanplatform/pelican (Go) < 0.0.0-20260408120501-7f73b9c3e677, fixed in 0.0.0-20260408120501-7f73b9c3e677. Check your lockfile, including transitive dependencies.

What it is

Pelican is a platform for creating data federations. From versions 7.21.0 to before 7.21.5, 7.22.0 to before 7.22.3, 7.23.0 to before 7.23.3, and 7.24.0 to before 7.24.2, there is a a privilege escalation vulnerability affecting Pelican's Web User Interface (WebUI). This attack allows any user authenticated to the WebUI via OAuth to gain admin privileges under certain configurations. This issue has been patched in versions 7.21.5, 7.22.3, 7.23.3, and 7.24.2.

From the GitHub advisory

Background

On April 2nd, 2026, a Claude coding agent alerted Pelican PI Brian Bockelman to a privilege escalation vulnerability affecting Pelican's Web User Interface (WebUI) for various versions between v7.21 and v7.24. Upon further investigation, the Pelican team discovered this attack allows any user authenticated to the WebUI via OAuth to gain admin privileges under certain configurations. These may include servers with the following configuration variables enabled:

- Server.UIAdminUsers: Affected if any of the listed admin users or the default admin account have not previously logged in to the server. - Server.AdminGroups: Affected if Issuer.GroupSource is set to internal and an admin of the group has not previously logged in to the server.

The OSDF operations team has mitigated these for core services, origins, and caches operated by the PATh project. However, mitigation may be needed for caches and origins not centrally operated.

Pelican Command Line has not currently identified any evidence this attack has been exploited in the services managed by OSDF operators.

Weakness type: CWE-863.

Product: github.com/pelicanplatform/pelican (Go) · Assigned by: GitHub_M · Published: 2026-05-09

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: present (depends on deployment conditions)
• Privileges required: low (any account)
• User interaction: none

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): 0.40% probability of exploitation activity in the next 30 days; percentile 33.

Timeline

• 2026-05-04 — GitHub-reviewed advisory GHSA-rpfr-x88x-xwcw published (critical)
• 2026-05-09 — CVE record published by GitHub_M
• 2026-05-12 — CVE record last updated

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-rpfr-x88x-xwcw github.com
2. CVE.org record CVE-2026-42571 cve.org
3. NVD entry CVE-2026-42571 nvd.nist.gov

Other references from the CVE record and advisory

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

Critical Go advisories · Today’s Security Digest