VulnerabilityPublished 9 Jul 2026

CVE-2026-52774: yeswiki/yeswiki · YesWiki Vulnerable to Reflected XSS via Unescaped `id` Parameter in Bazar Widget HTML Attributes

Affects yeswiki/yeswikiSource GCVE Database

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Not known to be exploited · public detection template (Nuclei) · CVSS 6.1 Medium : upgrade to 4.6.6 when convenient.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

6.1Medium

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

EPSS: 0.6% chance of exploitation in 30 days – higher than 51% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.6.6

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality: Low
Integrity: Low
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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
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: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 9 Jul 2026
Detectable: evidence found.
nuclei template: YesWiki Bazar Widget - Reflected XSS via 'id' Parameter
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
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), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 29 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 yeswiki/yeswiki to 4.6.6.

Affected software

Product	Affected	Fixed in
Packagistyeswiki/yeswiki	Affected <4.6.6	Fixed in 4.6.6

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

AI-suggested

If you cannot patch yet, users should consider disabling the Bazar extension if it is not needed or implement web application firewall (WAF) rules to detect and block suspicious requests targeting the `id` parameter in the widget route. Avoid exposing the vulnerable endpoint to untrusted users.

Description

YesWiki versions prior to 4.6.6 with the Bazar extension enabled are vulnerable to a reflected cross-site scripting (XSS) issue. The vulnerability arises because the `id` GET parameter is inserted into HTML attributes without proper escaping, using only `strip_tags()`, which does not neutralize double quotes. This allows attackers to inject arbitrary HTML attributes and JavaScript event handlers, leading to script execution in the victim's browser. The vulnerable endpoint is accessible without authentication or any access control checks, and does not require valid page tags or edit rights. An attacker can craft a URL that, when visited by a victim, triggers the injected script. This vulnerability is classified as CWE-79 and has a moderate severity rating.

Impact

An attacker can execute arbitrary JavaScript in the browser of any user who visits a crafted URL on a vulnerable YesWiki instance with Bazar enabled. This can lead to theft of sensitive browser-accessible data, session hijacking, and actions performed on behalf of the victim. The vulnerability requires no authentication or permissions and affects public visitors and logged-in users alike. There is no indication of denial of service or server-side impact.

Summary

YesWiki's Bazar widget handler reflects the `id` GET parameter into HTML attributes (`data-formid` and `data-iframeUrl`) using `strip_tags()` which only removes HTML tags but does not escape special characters like double quotes. This allows an attacker to break out of the attribute context and inject event handlers such as `onmouseover`, resulting in reflected XSS. The vulnerable route requires only the presence of the `id` parameter and the Bazar extension enabled; it performs no authentication or authorization checks. The vulnerability was confirmed on YesWiki version 4.6.5. The issue enables arbitrary JavaScript execution in the context of the YesWiki origin, affecting both unauthenticated and authenticated users.

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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CVE-2026-52774: yeswiki/yeswiki · YesWiki Vulnerable to Reflected XSS via Unescaped `id` Parameter in Bazar Widget HTML Attributes

Exploitation evidence

What to do

Affected software

Description

Impact

Summary

Nuclei detection templates

Proofs of concept on GitHub

References

Community reviews

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Jul 2026, 09:54 UTC

Public exploits and detectiona Nuclei detection template, GitHub proofs of concept

WeaknessesCWE-80

Technical details

References

Community reviews

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