CVE-2026-18312: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in Readwise Reader
Readwise Reader for Android constructs URLs in its WebView using attacker-controlled metadata without proper encoding or escaping. The application interpolates untrusted values directly into URL strings and inserts them into the DOM via innerHTML. Because the interpolation occurs without HTML or JavaScript context encoding, a crafted metadata value can break out of the intended URL structure and inject script content. An attacker could supply a document containing malicious metadata that, once synchronized to an Android device and rendered in the Reader WebView, results in execution of injected script content, enabling stored cross-site scripting (XSS)
AI Analysis
Technical Summary
Readwise Reader for Android versions >=8.7.2 <=8.10.1 improperly neutralizes input during web page generation by interpolating untrusted metadata values directly into URL strings and inserting them into the DOM via innerHTML without HTML or JavaScript context encoding. This flaw enables an attacker to supply crafted metadata that breaks out of the intended URL structure and injects script content, resulting in stored cross-site scripting (CWE-79). The vulnerability arises from lack of proper escaping or encoding of attacker-controlled input used in WebView URL construction.
Potential Impact
An attacker who supplies a document with malicious metadata can cause script execution within the Readwise Reader Android app's WebView when the document is synchronized and rendered. This stored XSS could potentially lead to unauthorized actions or data exposure within the app context. No known exploits in the wild have been reported.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are currently provided. Until a fix is available, users should exercise caution when synchronizing documents from untrusted sources. Monitor the vendor advisory at https://kb.cert.org/vuls/id/699627 for updates on remediation.
CVE-2026-18312: CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in Readwise Reader
Description
Readwise Reader for Android constructs URLs in its WebView using attacker-controlled metadata without proper encoding or escaping. The application interpolates untrusted values directly into URL strings and inserts them into the DOM via innerHTML. Because the interpolation occurs without HTML or JavaScript context encoding, a crafted metadata value can break out of the intended URL structure and inject script content. An attacker could supply a document containing malicious metadata that, once synchronized to an Android device and rendered in the Reader WebView, results in execution of injected script content, enabling stored cross-site scripting (XSS)
CVSS v3.1
Score 6.1medium
Affected software
Readwise
Reader
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Readwise Reader for Android versions >=8.7.2 <=8.10.1 improperly neutralizes input during web page generation by interpolating untrusted metadata values directly into URL strings and inserting them into the DOM via innerHTML without HTML or JavaScript context encoding. This flaw enables an attacker to supply crafted metadata that breaks out of the intended URL structure and injects script content, resulting in stored cross-site scripting (CWE-79). The vulnerability arises from lack of proper escaping or encoding of attacker-controlled input used in WebView URL construction.
Potential Impact
An attacker who supplies a document with malicious metadata can cause script execution within the Readwise Reader Android app's WebView when the document is synchronized and rendered. This stored XSS could potentially lead to unauthorized actions or data exposure within the app context. No known exploits in the wild have been reported.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are currently provided. Until a fix is available, users should exercise caution when synchronizing documents from untrusted sources. Monitor the vendor advisory at https://kb.cert.org/vuls/id/699627 for updates on remediation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- certcc
- Date Reserved
- 2026-07-29T17:45:56.191Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://kb.cert.org/vuls/id/699627","vendor":"CERT"}]
Threat ID: 6ab6a5d4f7a7c54106055638
Added to database: 09/25/2026, 16:48:20 UTC
Last enriched: 09/25/2026, 17:03:53 UTC
Last updated: 09/26/2026, 03:42:50 UTC
Views: 13
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