Exposure of resource to wrong sphere in Mozilla Firefox
Priority LOW 30CWE-668Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-668 and the CVSS impact.
Summary
The browser could have been confused into transferring a screen sharing state into another tab, which would leak unintended information. This vulnerability affects Firefox < 85.
Why it matters now
EPSS 0.00877 59th percentileScored 2026-11-07
Fix Fixed Firefox (Mozilla): 85
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Firefox (Mozilla) Fixed in 85
Timeline
- 2026-10-02 Threatist record created from CVE-2021-23958
- 2026-10-03 Alias added: GHSA-h8m9-2c4v-j2jx
References
More Mozilla Firefox vulnerabilities
- TI-2024-08981 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.8
- TI-2022-09832 Use after free in Mozilla Firefox KEVCVSS 3.1CRITICAL 9.6
- TI-2019-08769 Improper input validation in Mozilla Firefox ESR KEVCVSS 3.1CRITICAL 10.0
- TI-2010-03577 Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before… KEVCVSS 3.1CRITICAL 9.8
- TI-2023-04799 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
- TI-2023-04477 Out-of-bounds write in Google Chrome KEVCVSS 3.1HIGH 8.8
Sources
- CVE-2021-23958 · CVE Program
- CVE-2021-23958 · NVD
- FIRST EPSS
- GHSA-h8m9-2c4v-j2jx · GitHub Advisory Database · CC BY 4.0
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