CVE-2021-29944

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-06-24 · updated 2026-06-17
Weakness: CWE-79

Description

Lack of escaping allowed HTML injection when a webpage was viewed in Reader View. While a Content Security Policy prevents direct code execution, HTML injection is still possible. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 88.

Affected products

Mozilla Firefox: before 88.0 — fixed in 88.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 88.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1697604
https://www.mozilla.org/security/advisories/mfsa2021-16/
https://bugzilla.mozilla.org/show_bug.cgi?id=1697604
https://www.mozilla.org/security/advisories/mfsa2021-16/

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