XSS in Readwise Reader

CVE-2026-18311

Readwise Reader for Android contains a cross-site scripting vulnerability due to missing HTML sanitization in its processing of imported document metadata. Attacker-controlled fields such as the author meta tag are inserted into a WebView via innerHTML, enabling stored XSS that executes on synced devices when the malicious document is opened.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (11.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 11.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-18311: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-18311?
CVE-2026-18311 is a medium-severity vulnerability in Readwise Reader, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-09-25.
How severe is CVE-2026-18311?
Medium severity. CVSS v3 base score is 6.1 out of 10.