CVE-2026-2796
published 2026-02-24CVE-2026-2796: JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.
PriorityP349critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.95%
60.9th percentile
JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | firefox | < firefox 148.0-1 (sid) | firefox 148.0-1 (sid) |
| mozilla | firefox | < 148.0 | 148.0 |
| mozilla | firefox | — | — |
| mozilla | thunderbird | < 148.0 | 148.0 |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
osv9.8CRITICAL
vendor_debian9.8CRITICAL
vendor_redhat9.8CRITICAL
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Red Hat
kernel: vsock/virtio: avoid refilling the RX queue after teardown
vendor_redhat·2026-08-22·CVSS 7.8
CVE-2026-74613 [HIGH] CWE-825 kernel: vsock/virtio: avoid refilling the RX queue after teardown
kernel: vsock/virtio: avoid refilling the RX queue after teardown
In the Linux kernel, the following vulnerability has been resolved:
vsock/virtio: avoid refilling the RX queue after teardown
Commit b917507e5ad9 ("vsock/virtio: stop workers during the .remove()")
made the RX worker jump to its common exit when rx_run is clear. That
exit still refills the RX queue when the buffer count is low, so work
queued across virtio_vsock_vqs_del() can add buffers after the virtqueues
have been deleted.
BUG: KASAN: slab-use-after-free in virtqueue_add_sgs
Read of size 4 by task kworker/0:1
Workqueue: virtio_vsock virtio_transport_rx_work
Call Trace:
virtqueue_add_sgs (drivers/virtio/virtio_ring.c:2796)
virtio_vsock_rx_fill (net/vmw_vsock/virtio_transport.c:332)
virtio_transport_rx_work (net/vmw_vsock
Red Hat
firefox: thunderbird: JIT miscompilation in the JavaScript: WebAssembly component
vendor_redhat·2026-02-24·CVSS 9.8
CVE-2026-2796 [CRITICAL] firefox: thunderbird: JIT miscompilation in the JavaScript: WebAssembly component
firefox: thunderbird: JIT miscompilation in the JavaScript: WebAssembly component
JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability affects Firefox < 148 and Thunderbird < 148.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
JIT miscompilation in the JavaScript: WebAssembly component
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.
Package: firefox (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/firefox-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: rhel10/thunderbird-flatpak (Red Hat Enterprise Linux 10) - Not affected
Package: thunderbird (Red Hat Enterprise Linux 10) - Not aff
Debian
CVE-2026-2796: firefox - JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability ...
vendor_debian·2026·CVSS 9.8
CVE-2026-2796 [CRITICAL] CVE-2026-2796: firefox - JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability ...
JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability affects Firefox < 148 and Thunderbird < 148.
Scope: local
sid: resolved (fixed in 148.0-1)
Mozilla
Mozilla Foundation Security Advisory 2026-16: CVE-2026-2796
vendor_mozilla·CVSS 9.8
CVE-2026-2796 [CRITICAL] Mozilla Foundation Security Advisory 2026-16: CVE-2026-2796
Mozilla Foundation Security Advisory 2026-16
CVE: CVE-2026-2796
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 148
Mozilla
Mozilla Foundation Security Advisory 2026-13: CVE-2026-2796
vendor_mozilla·CVSS 9.8
CVE-2026-2796 [CRITICAL] Mozilla Foundation Security Advisory 2026-13: CVE-2026-2796
Mozilla Foundation Security Advisory 2026-13
CVE: CVE-2026-2796
Product: Firefox
Impact: high
Fixed in: Firefox 148
GHSA
GHSA-c3q8-4689-m4p6: JIT miscompilation in the JavaScript: WebAssembly component
ghsa_unreviewed·2026-02-24
CVE-2026-2796 [CRITICAL] CWE-843 GHSA-c3q8-4689-m4p6: JIT miscompilation in the JavaScript: WebAssembly component
JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability affects Firefox < 148.
OSV
CVE-2026-2796: JIT miscompilation in the JavaScript: WebAssembly component
osv·2026-02-24·CVSS 9.8
CVE-2026-2796 [CRITICAL] CVE-2026-2796: JIT miscompilation in the JavaScript: WebAssembly component
JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability affects Firefox < 148 and Thunderbird < 148.
No detection rules found.
No public exploits indexed.
Wiz
CVE-2026-2796 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 9.8
CVE-2026-2796 [CRITICAL] CVE-2026-2796 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-2796 :
NixOS vulnerability analysis and mitigation
JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability affects Firefox < 148 and Thunderbird < 148.
Source : NVD
## 9.8
Score
Published February 24, 2026
Severity CRITICAL
CNA Score 9.8
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) 24.9
Exploitation Probability (EPSS) 0.1
Affected packages and libraries
firefox
thunderbird
Sources
Homebrew Severity CRITICAL Has Fix Added at: Mar 03, 2026
Nix Severity CRITICAL Has Fix Added at: Mar 03, 2026
Ubuntu 22.04 Severity MEDIUM No Fix Added at: Mar 02, 2026
Linux Severity CRITICAL Has Fix Added at: Feb 2
Bugzilla
CVE-2026-74613 kernel: vsock/virtio: avoid refilling the RX queue after teardown
bugzilla·2026-08-22
CVE-2026-74613 [MEDIUM] CVE-2026-74613 kernel: vsock/virtio: avoid refilling the RX queue after teardown
CVE-2026-74613 kernel: vsock/virtio: avoid refilling the RX queue after teardown
In the Linux kernel, the following vulnerability has been resolved:
vsock/virtio: avoid refilling the RX queue after teardown
Commit b917507e5ad9 ("vsock/virtio: stop workers during the .remove()")
made the RX worker jump to its common exit when rx_run is clear. That
exit still refills the RX queue when the buffer count is low, so work
queued across virtio_vsock_vqs_del() can add buffers after the virtqueues
have been deleted.
BUG: KASAN: slab-use-after-free in virtqueue_add_sgs
Read of size 4 by task kworker/0:1
Workqueue: virtio_vsock virtio_transport_rx_work
Call Trace:
virtqueue_add_sgs (drivers/virtio/virtio_ring.c:2796)
virtio_vsock_rx_fill (net/vmw_vsock/virtio_transport.c:332)
virtio_transport_rx_w
https://bugzilla.mozilla.org/show_bug.cgi?id=2013165https://www.mozilla.org/security/advisories/mfsa2026-13/https://www.mozilla.org/security/advisories/mfsa2026-16/https://access.redhat.com/security/cve/CVE-2026-2796https://bugzilla.redhat.com/show_bug.cgi?id=2442301https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2796.json
2026-02-24
Published