CVE-2025-1942
published 2025-03-04CVE-2025-1942: When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string. This vulnerability…
PriorityP342critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.45%
36.1th percentile
When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string. This vulnerability was fixed in Firefox 136 and Thunderbird 136.
Affected
6 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | firefox | < firefox 136.0-1 (sid) | firefox 136.0-1 (sid) |
| mozilla | firefox | < 136.0 | 136.0 |
| mozilla | firefox | — | — |
| mozilla | firefox | >= 0 < 136.0+build3-0ubuntu0.20.04.1 | 136.0+build3-0ubuntu0.20.04.1 |
| mozilla | thunderbird | < 136.0 | 136.0 |
| mozilla | thunderbird | >= 0 < 1:140.7.1+build1-0ubuntu0.22.04.1 | 1:140.7.1+build1-0ubuntu0.22.04.1 |
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
vendor_ubuntu7.5HIGH
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OSV
firefox vulnerabilities
osv·2025-03-06·CVSS 7.5
CVE-2025-1933 [HIGH] firefox vulnerabilities
firefox vulnerabilities
Multiple security issues were discovered in Firefox. If a user were
tricked into opening a specially crafted website, an attacker could
potentially exploit these to cause a denial of service, obtain sensitive
information across domains, or execute arbitrary code. (CVE-2025-1933,
CVE-2025-1934, CVE-2025-1935, CVE-2025-1936, CVE-2025-1937, CVE-2025-1942)
It was discovered that Firefox did not properly handle WebTransport
connection, leading to a use-after-free vulnerability. An attacker could
potentially exploit this issue to cause a denial of service.
(CVE-2025-1931)
Ivan Fratric discovered that Firefox did not properly handle XSLT sorting,
leading to a out-of-bounds access vulnerability. An attacker could
potentially exploit this issue to cause a denial of servic
OSV
CVE-2025-1942: When String
osv·2025-03-04·CVSS 9.8
CVE-2025-1942 [CRITICAL] CVE-2025-1942: When String
When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string This vulnerability affects Firefox < 136 and Thunderbird < 136.
GHSA
GHSA-r83v-rmq7-r5m4: When String
ghsa_unreviewed·2025-03-04
CVE-2025-1942 [MEDIUM] CWE-908 GHSA-r83v-rmq7-r5m4: When String
When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string This vulnerability affects Firefox < 136.
Ubuntu
Thunderbird vulnerabilities
vendor_ubuntu·2026-02-02
CVE-2025-8031 Thunderbird vulnerabilities
Title: Thunderbird vulnerabilities
Summary: Several security issues were fixed in Thunderbird.
Multiple security issues were discovered in Thunderbird. If a user were
tricked into opening a specially crafted website in a browsing context,
an attacker could potentially exploit these to cause a denial of service,
obtain sensitive information, bypass security restrictions, cross-site
tracing, or execute arbitrary code.
Instructions: In general, a standard system update will make all the necessary changes.
Ubuntu
Firefox vulnerabilities
vendor_ubuntu·2025-03-06·CVSS 7.5
CVE-2025-1932 [HIGH] Firefox vulnerabilities
Title: Firefox vulnerabilities
Summary: Several security issues were fixed in Firefox.
Multiple security issues were discovered in Firefox. If a user were
tricked into opening a specially crafted website, an attacker could
potentially exploit these to cause a denial of service, obtain sensitive
information across domains, or execute arbitrary code. (CVE-2025-1933,
CVE-2025-1934, CVE-2025-1935, CVE-2025-1936, CVE-2025-1937, CVE-2025-1942)
It was discovered that Firefox did not properly handle WebTransport
connection, leading to a use-after-free vulnerability. An attacker could
potentially exploit this issue to cause a denial of service.
(CVE-2025-1931)
Ivan Fratric discovered that Firefox did not properly handle XSLT sorting,
leading to a out-of-bounds access vulnerability. An attacker
Red Hat
firefox: Disclosure of uninitialized memory when .toUpperCase() causes string to get longer
vendor_redhat·2025-03-04·CVSS 9.8
CVE-2025-1942 [CRITICAL] CWE-824 firefox: Disclosure of uninitialized memory when .toUpperCase() causes string to get longer
firefox: Disclosure of uninitialized memory when .toUpperCase() causes string to get longer
When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string This vulnerability affects Firefox < 136 and Thunderbird < 136.
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue: When String.toUpperCase() causes a string to get longer, it is possible for uninitialized memory to be incorporated into the result string.
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) - Fix deferred
Package: firefox-flatpak-container (Red Hat Enterprise Linux 10) - F
Debian
CVE-2025-1942: firefox - When String.toUpperCase() caused a string to get longer it was possible for unin...
vendor_debian·2025·CVSS 9.8
CVE-2025-1942 [CRITICAL] CVE-2025-1942: firefox - When String.toUpperCase() caused a string to get longer it was possible for unin...
When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated into the result string This vulnerability affects Firefox < 136 and Thunderbird < 136.
Scope: local
sid: resolved (fixed in 136.0-1)
Mozilla
Mozilla Foundation Security Advisory 2025-14: CVE-2025-1942
vendor_mozilla·CVSS 9.8
CVE-2025-1942 [CRITICAL] Mozilla Foundation Security Advisory 2025-14: CVE-2025-1942
Mozilla Foundation Security Advisory 2025-14
CVE: CVE-2025-1942
Product: Firefox
Impact: high
Fixed in: Firefox 136
Mozilla
Mozilla Foundation Security Advisory 2025-17: CVE-2025-1942
vendor_mozilla·CVSS 9.8
CVE-2025-1942 [CRITICAL] Mozilla Foundation Security Advisory 2025-17: CVE-2025-1942
Mozilla Foundation Security Advisory 2025-17
CVE: CVE-2025-1942
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 136
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2025-03-04
Published