VulnerabilityPublished 15 Sep 2026

CVE-2026-54503: plone.app.textfield · Basic XSS

Affects plone.app.textfieldSource CVE Database V5

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Not known to be exploited · CVSS 4.3 Medium · fixed in 4.0.1 : update plone.app.textfield when convenient.

Data as of 30 Oct 2026, 20:25 UTC

CVSS 3.1 base score

4.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.0.1, 3.0.2, 2.0.2

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade plone.app.textfield and plone/plone.app.textfield to 4.0.1, 3.0.2 or 2.0.2.

Affected software

Product	Affected	Fixed in
ploneplone.app.textfield	Affected >=4.0.0 <4.0.1	Fixed in 4.0.1
ploneplone.app.textfield	Affected >=3.0.0 <3.0.2	Fixed in 3.0.2
ploneplone.app.textfield	Affected <2.0.2	Fixed in 2.0.2
GitHubplone/plone.app.textfield`pkg:github/plone/plone.app.textfield`Other threats	Affected <2.0.2 >=3.0.0 <3.0.2 >=4.0.0 <4.0.1	Fixed in 2.0.2 3.0.2 4.0.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

This vulnerability is fixed in plone.app.textfield versions 2.0.2, 3.0.2, and 4.0.1. Users should upgrade to these or later versions to remediate the issue. No additional mitigation is indicated by the vendor advisory.

Description

plone.app.textfield provides a zope.schema-style field type called RichText for storing a value with a related MIME type. Prior to 2.0.2, 3.0.2, and 4.0.1, depending on the release line, RichTextValue.output returns an unsanitized stored RichText value when mimeType equals outputMimeType, including values that claim the text/x-html-safe output type. This equality shortcut bypasses the safe_html transform even though the transform itself correctly removes event-handler attributes and unsafe URI schemes. Equal types can result from a RichText field configured with the same mimeType and outputMimeType or from REST API input that supplies text/x-html-safe as its content type. The raw stored value is then emitted through tal:content=structure without escaping, allowing a user who can set a RichText field to store JavaScript that executes in a viewer's browser. This issue is fixed in versions 2.0.2, 3.0.2, and 4.0.1.

Impact

An attacker with permission to set a RichText field can inject JavaScript that executes in the browsers of users viewing the affected content. This can lead to limited confidentiality impact (CVSS impact score reflects low confidentiality impact), but no integrity or availability impact is indicated. The vulnerability requires low attack complexity and privileges but no user interaction.

Summary

The vulnerability in plone.app.textfield involves improper neutralization of script-related HTML tags (CWE-80) in the RichText field type. When the stored RichText mimeType matches the outputMimeType, the safe_html transform is bypassed, causing the raw stored value to be emitted without escaping. This enables stored cross-site scripting (XSS) attacks by allowing JavaScript injection through the RichText field. The flaw affects versions prior to 2.0.2, 3.0.2, and 4.0.1 depending on the release line. The issue is resolved by applying the fixes in these versions.

CWE-80Improper Neutralization of Script-Related HTML Tags in a Web Page (opens in a new tab)
Variant weaknessLikelihood of exploit: HighOWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.
Implementation
Carefully check each input parameter against a rigorous positive specification (allowlist) defining the specific characters and format allowed. All input should be neutralized, not just parameters that the user is supposed to specify, but all data in the request, including hidden fields, cookies, headers, the URL…
Implementation · Output Encoding
Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8.
Implementation
With Struts, write all data from form beans with the bean's filter attribute set to true.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V1.5.1 (opens in a new tab)
V5.3.3 (opens in a new tab)
Attack patterns
XSS Targeting Non-Script Elements (opens in a new tab)
PHP Remote File Inclusion (opens in a new tab)
XSS Through HTTP Query Strings (opens in a new tab)
XSS Through HTTP Headers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 15 Sep 2026, 17:02 UTC

WeaknessesCWE-80

Technical details

References

Community reviews

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