CVE-2026-4716
published 2026-03-24CVE-2026-4716: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9…
PriorityP347critical9.1CVSS 3.1
AVNACLPRNUINSUCHINAH
EPSS
0.41%
33.3th percentile
Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Affected
10 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | firefox | < firefox 149.0-1 (sid) | firefox 149.0-1 (sid) |
| debian | firefox-esr | < firefox 149.0-1 (sid) | firefox 149.0-1 (sid) |
| debian | thunderbird | < firefox 149.0-1 (sid) | firefox 149.0-1 (sid) |
| mozilla | firefox | < 140.9.0 | 140.9.0 |
| mozilla | firefox | < 149.0 | 149.0 |
| mozilla | firefox | — | — |
| mozilla | thunderbird | >= 0 < 1:140.9.0esr-1~deb11u1 | 1:140.9.0esr-1~deb11u1 |
| mozilla | thunderbird | >= 0 < 1:140.9.0esr-1~deb12u1 | 1:140.9.0esr-1~deb12u1 |
| mozilla | thunderbird | >= 0 < 1:140.9.0esr-1~deb13u1 | 1:140.9.0esr-1~deb13u1 |
| mozilla | thunderbird | >= 0 < 1:140.9.0esr-1 | 1:140.9.0esr-1 |
CVSS provenance
nvdv3.19.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
osv9.1CRITICAL
vendor_debian9.1CRITICAL
vendor_redhat9.1CRITICAL
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GHSA
Gitea SSH Key Parser Denial of Service
ghsa·2026-07-21
CVE-2026-56657 [MEDIUM] CWE-400 Gitea SSH Key Parser Denial of Service
Gitea SSH Key Parser Denial of Service
Gitea's SSH key ingestion endpoint accepts keys in RFC 4716 (SSH2) format and normalises them before storage. The normalisation function contains an O(N²) string concatenation loop with no input size limit, meaning a single malicious key submission can force the server to perform an amount of work that grows quadratically with the size of the input. Any authenticated user can exploit this to exhaust the server's CPU and memory, taking the instance offline.
### Root Cause
An attacker sends a POST /api/v1/user/keys request with a Bearer token and a JSON body whose key field contains a malicious RFC 4716 (SSH2) public key. The key consists of a valid SSH2 header followed by a very large number of short content lines — for example, 400,000 lines of 100
GHSA
GHSA-r67f-xmr7-94cc: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component
ghsa_unreviewed·2026-03-24
CVE-2026-4716 [CRITICAL] CWE-908 GHSA-r67f-xmr7-94cc: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component
Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9.
OSV
CVE-2026-4716: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component
osv·2026-03-24·CVSS 9.1
CVE-2026-4716 [CRITICAL] CVE-2026-4716: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component
Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
Red Hat
firefox: thunderbird: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component
vendor_redhat·2026-03-24·CVSS 9.1
CVE-2026-4716 [CRITICAL] CWE-824 firefox: thunderbird: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component
firefox: thunderbird: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component
Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Incorrect boundary conditions, uninitialized memory in the JavaScript Engine 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
Package
Debian
CVE-2026-4716: firefox - Incorrect boundary conditions, uninitialized memory in the JavaScript Engine com...
vendor_debian·2026·CVSS 9.1
CVE-2026-4716 [CRITICAL] CVE-2026-4716: firefox - Incorrect boundary conditions, uninitialized memory in the JavaScript Engine com...
Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
Scope: local
sid: resolved (fixed in 149.0-1)
Mozilla
Mozilla Foundation Security Advisory 2026-20: CVE-2026-4716
vendor_mozilla·CVSS 9.1
CVE-2026-4716 [CRITICAL] Mozilla Foundation Security Advisory 2026-20: CVE-2026-4716
Mozilla Foundation Security Advisory 2026-20
CVE: CVE-2026-4716
Product: Firefox
Impact: high
Fixed in: Firefox 149
Mozilla
Mozilla Foundation Security Advisory 2026-22: CVE-2026-4716
vendor_mozilla·CVSS 9.1
CVE-2026-4716 [CRITICAL] Mozilla Foundation Security Advisory 2026-22: CVE-2026-4716
Mozilla Foundation Security Advisory 2026-22
CVE: CVE-2026-4716
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.9
Mozilla
Mozilla Foundation Security Advisory 2026-24: CVE-2026-4716
vendor_mozilla·CVSS 9.1
CVE-2026-4716 [CRITICAL] Mozilla Foundation Security Advisory 2026-24: CVE-2026-4716
Mozilla Foundation Security Advisory 2026-24
CVE: CVE-2026-4716
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.9
Mozilla
Mozilla Foundation Security Advisory 2026-23: CVE-2026-4716
vendor_mozilla·CVSS 9.1
CVE-2026-4716 [CRITICAL] Mozilla Foundation Security Advisory 2026-23: CVE-2026-4716
Mozilla Foundation Security Advisory 2026-23
CVE: CVE-2026-4716
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 149
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-4716 firefox: thunderbird: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component
bugzilla·2026-03-24·CVSS 9.1
CVE-2026-4716 [CRITICAL] CVE-2026-4716 firefox: thunderbird: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component
CVE-2026-4716 firefox: thunderbird: Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component
Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9.
Discussion:
This issue has been addressed in the following products:
Red Hat Enterprise Linux 10
Via RHSA-2026:5931 https://access.redhat.com/errata/RHSA-2026:5931
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 9
Via RHSA-2026:5930 https://access.redhat.com/errata/RHSA-2026:5930
---
This issue has been addressed in the following products:
Red Hat Enterprise Linux 8
Via RHSA-2026:5932 https://access.redhat.com/errata/RHSA-2026:5932
---
This issue has been addressed
Wiz
CVE-2026-4716 Impact, Exploitability, and Mitigation Steps | Wiz
blogs_wiz·CVSS 7.5
CVE-2026-4716 [HIGH] CVE-2026-4716 Impact, Exploitability, and Mitigation Steps | Wiz
## CVE-2026-4716 :
NixOS vulnerability analysis and mitigation
Incorrect boundary conditions, uninitialized memory in the JavaScript Engine component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
Source : NVD
## 9.1
Score
Published March 24, 2026
Severity CRITICAL
CNA Score 9.1
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) 6
Exploitation Probability (EPSS) N/A
Affected packages and libraries
cpe:2.3:a:mozilla:firefox
MozillaFirefox
Sources
AlmaLinux 8 Severity HIGH Has Fix Added at: Mar 31, 2026
AlmaLinux 9 Severity HIGH Has Fix Added at: Mar 31, 2026
Chainguard Has Fix
2026-03-24
Published