CVE-2026-2783
published 2026-02-24CVE-2026-2783: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8…
PriorityP340high7.5CVSS 3.1
AVNACLPRNUINSUCHINAN
EPSS
0.29%
20.6th percentile
Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
Affected
12 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | firefox | < firefox 148.0-1 (sid) | firefox 148.0-1 (sid) |
| debian | firefox-esr | < firefox 148.0-1 (sid) | firefox 148.0-1 (sid) |
| debian | thunderbird | < firefox 148.0-1 (sid) | firefox 148.0-1 (sid) |
| mozilla | firefox | < 140.8.0 | 140.8.0 |
| mozilla | firefox | < 148.0 | 148.0 |
| mozilla | firefox | — | — |
| mozilla | thunderbird | < 140.8.0 | 140.8.0 |
| mozilla | thunderbird | < 148.0 | 148.0 |
| mozilla | thunderbird | >= 0 < 1:140.8.0esr-1~deb11u1 | 1:140.8.0esr-1~deb11u1 |
| mozilla | thunderbird | >= 0 < 1:140.8.0esr-1~deb12u1 | 1:140.8.0esr-1~deb12u1 |
| mozilla | thunderbird | >= 0 < 1:140.8.0esr-1~deb13u1 | 1:140.8.0esr-1~deb13u1 |
| mozilla | thunderbird | >= 0 < 1:140.8.0esr-1 | 1:140.8.0esr-1 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
osv7.5HIGH
vendor_debian7.5HIGH
vendor_redhat7.5HIGH
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Red Hat
firefox: thunderbird: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
vendor_redhat·2026-02-24·CVSS 7.5
CVE-2026-2783 [HIGH] firefox: thunderbird: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
firefox: thunderbird: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Affected
P
Debian
CVE-2026-2783: firefox - Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT c...
vendor_debian·2026·CVSS 7.5
CVE-2026-2783 [HIGH] CVE-2026-2783: firefox - Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT c...
Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
Scope: local
sid: resolved (fixed in 148.0-1)
Mozilla
Mozilla Foundation Security Advisory 2026-16: CVE-2026-2783
vendor_mozilla·CVSS 7.5
CVE-2026-2783 [HIGH] Mozilla Foundation Security Advisory 2026-16: CVE-2026-2783
Mozilla Foundation Security Advisory 2026-16
CVE: CVE-2026-2783
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 148
Mozilla
Mozilla Foundation Security Advisory 2026-15: CVE-2026-2783
vendor_mozilla·CVSS 7.5
CVE-2026-2783 [HIGH] Mozilla Foundation Security Advisory 2026-15: CVE-2026-2783
Mozilla Foundation Security Advisory 2026-15
CVE: CVE-2026-2783
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.8
Mozilla
Mozilla Foundation Security Advisory 2026-13: CVE-2026-2783
vendor_mozilla·CVSS 7.5
CVE-2026-2783 [HIGH] Mozilla Foundation Security Advisory 2026-13: CVE-2026-2783
Mozilla Foundation Security Advisory 2026-13
CVE: CVE-2026-2783
Product: Firefox
Impact: high
Fixed in: Firefox 148
Mozilla
Mozilla Foundation Security Advisory 2026-17: CVE-2026-2783
vendor_mozilla·CVSS 7.5
CVE-2026-2783 [HIGH] Mozilla Foundation Security Advisory 2026-17: CVE-2026-2783
Mozilla Foundation Security Advisory 2026-17
CVE: CVE-2026-2783
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.8
GHSA
GHSA-7xqm-gm4h-p23x: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
ghsa_unreviewed·2026-02-24
CVE-2026-2783 [HIGH] CWE-200 GHSA-7xqm-gm4h-p23x: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148 and Firefox ESR < 140.8.
OSV
CVE-2026-2783: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
osv·2026-02-24·CVSS 7.5
CVE-2026-2783 [HIGH] CVE-2026-2783: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-2783 firefox: thunderbird: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
bugzilla·2026-02-24·CVSS 7.5
CVE-2026-2783 [HIGH] CVE-2026-2783 firefox: thunderbird: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
CVE-2026-2783 firefox: thunderbird: Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component
Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148 and Firefox ESR < 140.8.
Discussion:
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2026:3338 https://access.redhat.com/errata/RHSA-2026:3338
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 9
Via RHSA-2026:3339 https://access.redhat.com/errata/RHSA-2026:3339
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 10
Via RHSA-2026:3361 https://access.redhat.com/errata/RHSA-2026:3361
---
This issue has been addres
Wiz
CVE-2026-2783 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 7.5
CVE-2026-2783 [HIGH] CVE-2026-2783 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-2783 :
NixOS vulnerability analysis and mitigation
Information disclosure due to JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
Source : NVD
## 7.5
Score
Published February 24, 2026
Severity HIGH
CNA Score 6.5
Affected Technologies
NixOS
Mozilla Firefox
Has Public Exploit No
Has CISA KEV Exploit No
CISA KEV Release Date N/A
CISA KEV Due Date N/A
Exploitation Probability Percentile (EPSS) 12.1
Exploitation Probability (EPSS) N/A
Affected packages and libraries
firefox-debugsource
rhel10::firefox-flatpak
Sources
AlmaLinux 8 Severity HIGH Has Fix Added at: Mar 03, 2026
AlmaLinux 9 Severity HIGH Has Fix Added at: Mar 02, 2026
Debian 11, 1
2026-02-24
Published