CVE-2026-15803
XXE in Eclipse RDF4J XML parsers enables file disclosure, SSRF or DoS.
Is CVE-2026-15803 being exploited?
Not confirmed. CVE-2026-15803 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.34% probability of exploitation in the next 30 days.
How severe is CVE-2026-15803?
CVE-2026-15803 is rated High with a CVSS score of 8.7. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-15803?
Yes. A fix has been recorded for CVE-2026-15803. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-15803 affect?
CVE-2026-15803 affects Eclipse RDF4J < 5.3.2, Applications parsing RDF/XML or XML query results with RDF4J. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-15803?
Upgrade to RDF4J 5.3.2; disable external entities; validate/restrict XML inputs.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
XXE via untrusted XML allows local file read, SSRF and denial-of-service when RDF4J parses XML.
Patch when possible
- affected< 5.3.2
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.