What’s Vulnerable › Vulnerabilities

CVE-2022-31736

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-12-22 · updated 2026-06-17
• Weakness: CWE-942

Description

A malicious website could have learned the size of a cross-origin resource that supported Range requests. This vulnerability affects Thunderbird < 91.10, Firefox < 101, and Firefox ESR < 91.10.

Affected products

• Mozilla Firefox: before 101 — fixed in 101
• Mozilla Firefox ESR: before 91.10 — fixed in 91.10
• Mozilla Thunderbird: before 91.10 — fixed in 91.10

How to fix

Upgrade to a fixed version: Mozilla Firefox 101; Mozilla Firefox ESR 91.10; Mozilla Thunderbird 91.10. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1735923
• https://www.mozilla.org/security/advisories/mfsa2022-20/
• https://www.mozilla.org/security/advisories/mfsa2022-21/
• https://www.mozilla.org/security/advisories/mfsa2022-22/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1735923
• https://www.mozilla.org/security/advisories/mfsa2022-20/
• https://www.mozilla.org/security/advisories/mfsa2022-21/
• https://www.mozilla.org/security/advisories/mfsa2022-22/

Get alerted when CVE-2022-31736 or the next vulnerability affects your stack