CVE-2026-2790: Same-origin policy bypass in the Networking: JAR component
Same-origin policy bypass in the Networking: JAR component. This vulnerability affects Firefox < 148 and Firefox ESR < 140.8.
Other sources
Same-origin policy bypass in the Networking: JAR component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 148 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 140.8 - Upgrade
Upgrade
Firefoxto a version that resolves this vulnerability.Fixed in 148 - Upgrade
Upgrade
Firefox ESRto a version that resolves this vulnerability.Fixed in 140.8 - Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 148 - Upgrade
Upgrade
Thunderbirdto a version that resolves this vulnerability.Fixed in 140.8
Event History
Parent advisories
This vulnerability appears in the following advisories.
Peer vulnerabilities
Found alongside the following vulnerabilities.
- CVE-2026-2757
- CVE-2026-2758
- CVE-2026-2759
- CVE-2026-2795
- CVE-2026-2760
- CVE-2026-2761
- CVE-2026-2762
- CVE-2026-2763
- CVE-2026-2764
- CVE-2026-2796
- CVE-2026-2797
- CVE-2026-2765
- CVE-2026-2766
- CVE-2026-2767
- CVE-2026-2768
- CVE-2026-2798
- CVE-2026-2769
- CVE-2026-2799
- CVE-2026-2770
- CVE-2026-2771
- CVE-2026-2772
- CVE-2026-2773
- CVE-2026-2774
- CVE-2026-2775
- CVE-2026-2776
- CVE-2026-2777
- CVE-2026-2778
- CVE-2026-2779
- CVE-2026-2800
- CVE-2026-2780
- CVE-2026-2781
- CVE-2026-2801
- CVE-2026-2782
- CVE-2026-2783
- CVE-2026-2802
- CVE-2026-2803
- CVE-2026-2784
- CVE-2026-2785
- CVE-2026-2804
- CVE-2026-2786
- CVE-2026-2805
- CVE-2026-2787
- CVE-2026-2788
- CVE-2026-2789
- CVE-2026-2806
- CVE-2026-2790
- CVE-2026-2791
- CVE-2026-2807
- CVE-2026-2792
- CVE-2026-2793
- CVE-2026-2794
Frequently Asked Questions
What is the severity of CVE-2026-2790?
CVE-2026-2790 is classified as a high-severity vulnerability due to its potential for bypassing the same-origin policy.
How do I fix CVE-2026-2790?
To fix CVE-2026-2790, update your Firefox browser to version 148 or higher, or Firefox ESR to version 140.8 or higher.
What products are affected by CVE-2026-2790?
CVE-2026-2790 affects Mozilla Firefox versions below 148 and Firefox ESR versions below 140.8.
What does the same-origin policy mean in relation to CVE-2026-2790?
The same-origin policy is a security measure that restricts how a document or script from one origin can interact with resources from another origin, and CVE-2026-2790 allows a bypass of this mechanism.
What are the potential impacts of CVE-2026-2790?
The potential impacts of CVE-2026-2790 include unauthorized access to sensitive data and possible exploitation of vulnerable systems.