CVE-2026-2790
Same-origin policy bypass in the Networking: JAR component
Description
Same-origin policy bypass in the Networking: JAR component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
INFO
Published Date :
Feb. 24, 2026, 2:16 p.m.
Last Modified :
Feb. 26, 2026, 9:28 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-2790
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update Firefox to version 148 or later.
- Update Firefox ESR to version 140.8 or later.
Public PoC/Exploit Available at Github
CVE-2026-2790 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-2790.
| URL | Resource |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=2008426 | Issue Tracking Permissions Required |
| https://www.mozilla.org/security/advisories/mfsa2026-13/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2026-15/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2026-16/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2026-17/ | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-2790 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-2790
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
DSA and DLA for Debian last 14 days
Python
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-2790 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-2790 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Feb. 26, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-346 -
Initial Analysis by [email protected]
Feb. 25, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* versions up to (excluding) 148.0 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:* versions up to (excluding) 148.0 *cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* versions up to (excluding) 140.8.0 *cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* versions up to (excluding) 140.8.0 Added Reference Type Mozilla Corporation: https://bugzilla.mozilla.org/show_bug.cgi?id=2008426 Types: Issue Tracking, Permissions Required Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-13/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-15/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-16/ Types: Vendor Advisory Added Reference Type Mozilla Corporation: https://www.mozilla.org/security/advisories/mfsa2026-17/ Types: Vendor Advisory -
CVE Modified by [email protected]
Feb. 24, 2026
Action Type Old Value New Value Changed Description Same-origin policy bypass in the Networking: JAR component. This vulnerability affects Firefox < 148 and Firefox ESR < 140.8. Same-origin policy bypass in the Networking: JAR component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8. Added Reference https://www.mozilla.org/security/advisories/mfsa2026-16/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-17/ -
New CVE Received by [email protected]
Feb. 24, 2026
Action Type Old Value New Value Added Description Same-origin policy bypass in the Networking: JAR component. This vulnerability affects Firefox < 148 and Firefox ESR < 140.8. Added Reference https://bugzilla.mozilla.org/show_bug.cgi?id=2008426 Added Reference https://www.mozilla.org/security/advisories/mfsa2026-13/ Added Reference https://www.mozilla.org/security/advisories/mfsa2026-15/