CVE-2026-54503

MEDIUMPre-NVD 4.34.3
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 4.3 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: cna:github_m
4.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: —CVSS: 4.3Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

plone.app.textfield: Stored XSS by spoofing mime type

Impact

A stored XSS affecting RichText fields. RichTextValue.output returns the raw, unsanitized stored value whenever the stored mimeType equals the outputMimeType. Because the safe-HTML output type (text/x-html-safe) is the type that signifies "already sanitized", any value whose stored mimeType equals it bypasses the safe_html transform entirely on render. The transform itself is sound — it correctly strips on* event-handler attributes and javascript:/data: URIs; the defect is that it is never invoked for these values. The unsanitized value is then emitted via tal:content="structure ...", which performs no escaping, so the payload executes in the viewer's browser.

This can be a problem when a RichText field is wrongly defined in code with a mimeType and outputMimeType that are the same, or when the REST API is used to the same effect.

Patches

The problem has been patched:

* For Plone 6.0, upgrade plone.app.textfield to 2.0.2. * For Plone 6.1, upgrade plone.app.textfield to 3.0.2. * For Plone 6.2, upgrade plone.app.textfield to 4.0.1.

Workarounds

There is no known workaround.

CVSS v3
4.3
EG Score
4.3(low)
EG Risk
24(Track)
EG Risk 24/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity43% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
—
KEV
Not listed

Published

July 17, 2026

Last Modified

July 17, 2026

Vendor Advisories for CVE-2026-54503(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
plone-app-textfield4.0.04.0.1—

Data Freshness Timeline

(refreshed 2× in last 7d / 2× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-23 03:19 UTCEG score recompute
  2. 2026-07-17 19:00 UTCEG score recompute

Frequently asked(4)

What is CVE-2026-54503?
CVE-2026-54503 is a medium vulnerability published on July 17, 2026. plone.app.textfield: Stored XSS by spoofing mime type Impact A stored XSS affecting RichText fields. RichTextValue.output returns the raw, unsanitized stored value whenever the stored mimeType equals the outputMimeType. Because the safe-HTML output type (text/x-html-safe) is the type that signifies…
When was CVE-2026-54503 disclosed?
CVE-2026-54503 was first published in the National Vulnerability Database on July 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-54503?
CVE-2026-54503 has a CVSS v4.0 base score of 4.3 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-54503?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54503, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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