CVE-2026-45083: Goobi viewer - Core: Unauthenticated Solr Streaming Expression Proxy

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 0.7%, percentile 51: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 51% of all scored CVEs (moderate). 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 io.goobi.viewer:viewer-core (Maven) >= 4.8.0, <= 26.04, no fixed version listed. Check your lockfile, including transitive dependencies.

What it is

The Goobi viewer is a web application that allows digitised material to be displayed in a web browser. From 4.8.0 to before 26.04.1, the Goobi viewer REST endpoint POST /api/v1/index/stream accepted an arbitrary Solr streaming expression from unauthenticated network clients and forwarded it to the backend Solr server without restriction. An attacker could read the complete Solr index and, in default Solr deployments, also modify or delete indexed records. This vulnerability is fixed in 26.04.1.

From the GitHub advisory

Summary

The Goobi viewer REST endpoint POST /api/v1/index/stream accepted an arbitrary Solr streaming expression from unauthenticated network clients and forwarded it to the backend Solr server without restriction. An attacker could read the complete Solr index and, in default Solr deployments, also modify or delete indexed records.

The API endpoint has now been removed.

Impact

- Complete Solr index read without authentication. All documents indexed by the viewer including those protected by access conditions such as moving walls, licence requirements or IP restrictions - can be read in full.

Weakness type: CWE-306.

Product: io.goobi.viewer:viewer-core (Maven) · Assigned by: GitHub_M · Published: 2026-05-27

Affected and fixed versions

Severity scores

• 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): 0.65% probability of exploitation activity in the next 30 days; percentile 51.

Timeline

• 2026-05-13 — GitHub-reviewed advisory GHSA-2rgp-f66f-4499 published (critical)
• 2026-05-27 — CVE record published by GitHub_M
• 2026-05-28 — 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-2rgp-f66f-4499 github.com
2. CVE.org record CVE-2026-45083 cve.org
3. NVD entry CVE-2026-45083 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
4. github.com github.com

Critical Maven advisories · Today’s Security Digest