CVE-2026-100821: Site isolation issue in the Panning and Zooming component

Affected Software

Remediation

Recommended actions to resolve this vulnerability, in priority order.

1. Upgrade

   Upgrade to a fixed release to a version that resolves this vulnerability.

   Fixed in 115.42
2. Upgrade

   Upgrade to a fixed release to a version that resolves this vulnerability.

   Fixed in 140.17
3. Upgrade

   Upgrade to a fixed release to a version that resolves this vulnerability.

   Fixed in 157
4. Upgrade

   Upgrade to a fixed release to a version that resolves this vulnerability.

   Fixed in 153.4
5. Upgrade

   Upgrade Firefox ESR to a version that resolves this vulnerability.

   Fixed in 153.4
6. Upgrade

   Upgrade Firefox to a version that resolves this vulnerability.

   Fixed in 157
7. Upgrade

   Upgrade Firefox ESR to a version that resolves this vulnerability.

   Fixed in 115.42
8. Upgrade

   Upgrade Firefox ESR to a version that resolves this vulnerability.

   Fixed in 140.17

Event History

Parent advisories

This vulnerability appears in the following advisories.

• MFSA2026-98
• MFSA2026-99
• MFSA2026-97
• MFSA2026-100

Peer vulnerabilities

Found alongside the following vulnerabilities.

• CVE-2026-100756
• CVE-2026-100757
• CVE-2026-100758
• CVE-2026-100759
• CVE-2026-100762
• CVE-2026-92035
• CVE-2026-100766
• CVE-2026-100767
• CVE-2026-100770
• CVE-2026-100771
• CVE-2026-100773
• CVE-2026-100774
• CVE-2026-100775
• CVE-2026-100777
• CVE-2026-100778
• CVE-2026-100779
• CVE-2026-100780
• CVE-2026-100781
• CVE-2026-100782
• CVE-2026-100783
• CVE-2026-100784
• CVE-2026-100785
• CVE-2026-100786
• CVE-2026-100789
• CVE-2026-100790
• CVE-2026-100791
• CVE-2026-100832
• CVE-2026-100797
• CVE-2026-100803
• CVE-2026-100819
• CVE-2026-100821
• CVE-2026-100769
• CVE-2026-100772
• CVE-2026-100776
• CVE-2026-100788
• CVE-2026-100792
• CVE-2026-100794
• CVE-2026-96869
• CVE-2026-100801
• CVE-2026-100807
• CVE-2026-100811
• CVE-2026-100818
• CVE-2026-100820
• CVE-2026-100760
• CVE-2026-100761
• CVE-2026-100763
• CVE-2026-100764
• CVE-2026-100765
• CVE-2026-100768
• CVE-2026-100787
• CVE-2026-100793
• CVE-2026-100795
• CVE-2026-100796
• CVE-2026-100798
• CVE-2026-100799
• CVE-2026-100800
• CVE-2026-100802
• CVE-2026-100804
• CVE-2026-100805
• CVE-2026-100806
• CVE-2026-100808
• CVE-2026-100809
• CVE-2026-100810
• CVE-2026-100812
• CVE-2026-100813
• CVE-2026-100814
• CVE-2026-100815
• CVE-2026-100816
• CVE-2026-100817
• CVE-2026-100822
• CVE-2026-100823
• CVE-2026-100824
• CVE-2026-100825
• CVE-2026-100826
• CVE-2026-100828
• CVE-2026-100829
• CVE-2026-100830
• CVE-2026-100831