CVE-2026-55248
RSS portlet in plone.app.portlets enables memory DoS, SSRF, and stored XSS via malicious feed URLs.
Is CVE-2026-55248 being exploited?
Not confirmed. CVE-2026-55248 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 0.32% probability of exploitation in the next 30 days.
How severe is CVE-2026-55248?
CVE-2026-55248 is rated Critical with a CVSS score of 9.1. 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-2026-55248?
Yes. A fix has been recorded for CVE-2026-55248. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-55248 affect?
CVE-2026-55248 affects plone.app.portlets <5.0.8, <6.0.4, <7.0.2, Plone CMS instances using plone.app.portlets. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-55248?
Upgrade to 5.0.8 / 6.0.4 / 7.0.2; block untrusted RSS and restrict internal URL access.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated user able to add RSS portlet can cause memory exhaustion DoS, perform SSRF/internal port probes, and inject stored XSS.
Immediate action required
- affected< 5.0.8
- affected>= 6.0.0 and < 6.0.4
- affected>= 7.0.0 and < 7.0.2
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.