CVE-2025-1020
published 2025-02-04CVE-2025-1020: Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bugs showed evidence of memory corruption and we presume that with enough effort…
PriorityP344critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.52%
40.9th percentile
Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 135 and Thunderbird 135.
Affected
6 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | firefox | < firefox 135.0-1 (sid) | firefox 135.0-1 (sid) |
| mozilla | firefox | < 135.0 | 135.0 |
| mozilla | firefox | — | — |
| mozilla | firefox | >= 0 < 135.0+build2-0ubuntu0.20.04.1 | 135.0+build2-0ubuntu0.20.04.1 |
| mozilla | thunderbird | >= 0 < 1:140.7.1+build1-0ubuntu0.22.04.1 | 1:140.7.1+build1-0ubuntu0.22.04.1 |
| mozilla | thunderbird | >= 131.0 < 135.0 | 135.0 |
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
vendor_ubuntu9.8CRITICAL
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OSV
firefox vulnerabilities
osv·2025-02-11·CVSS 9.8
CVE-2025-1011 [CRITICAL] 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-2025-1011,
CVE-2025-1013, CVE-2025-1014, CVE-2025-1016, CVE-2025-1017, CVE-2025-1018,
CVE-2025-1019, CVE-2025-1020)
Ivan Fratric discovered that Firefox did not properly handle XSLT data,
leading to a use-after-free vulnerability. An attacker could potentially
exploit this issue to cause a denial of service, or execute arbitrary code.
(CVE-2025-1009)
Atte Kettunen discovered that Firefox did not properly manage memory in
the Custom Highlight API, leading to a use-after-free vulnerability. An
attacke
OSV
CVE-2025-1020: Memory safety bugs present in Firefox 134 and Thunderbird 134
osv·2025-02-04·CVSS 9.8
CVE-2025-1020 [CRITICAL] CVE-2025-1020: Memory safety bugs present in Firefox 134 and Thunderbird 134
Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 135 and Thunderbird < 135.
GHSA
GHSA-x7w4-wjh5-78hj: Memory safety bugs present in Firefox 134 and Thunderbird 134
ghsa_unreviewed·2025-02-04
CVE-2025-1020 [CRITICAL] CWE-787 GHSA-x7w4-wjh5-78hj: Memory safety bugs present in Firefox 134 and Thunderbird 134
Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 135 and Thunderbird < 135.
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·2025-02-11·CVSS 9.8
CVE-2025-1016 [CRITICAL] 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-2025-1011,
CVE-2025-1013, CVE-2025-1014, CVE-2025-1016, CVE-2025-1017, CVE-2025-1018,
CVE-2025-1019, CVE-2025-1020)
Ivan Fratric discovered that Firefox did not properly handle XSLT data,
leading to a use-after-free vulnerability. An attacker could potentially
exploit this issue to cause a denial of service, or execute arbitrary code.
(CVE-2025-1009)
Atte Kettunen discovered that Firefox did not properly manage memory in
the Custom High
Red Hat
firefox: thunderbird: Memory safety bugs fixed in Firefox 135 and Thunderbird 135
vendor_redhat·2025-02-04·CVSS 9.8
CVE-2025-1020 [CRITICAL] CWE-120 firefox: thunderbird: Memory safety bugs fixed in Firefox 135 and Thunderbird 135
firefox: thunderbird: Memory safety bugs fixed in Firefox 135 and Thunderbird 135
Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 135 and Thunderbird < 135.
A flaw was found in Firefox. The Mozilla Foundation's Security Advisory describes the following issue: Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.
Statement: Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundatio
Debian
CVE-2025-1020: firefox - Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bug...
vendor_debian·2025·CVSS 9.8
CVE-2025-1020 [CRITICAL] CVE-2025-1020: firefox - Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bug...
Memory safety bugs present in Firefox 134 and Thunderbird 134. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 135 and Thunderbird < 135.
Scope: local
sid: resolved (fixed in 135.0-1)
Mozilla
Mozilla Foundation Security Advisory 2025-11: CVE-2025-1020
vendor_mozilla·CVSS 9.8
CVE-2025-1020 [CRITICAL] Mozilla Foundation Security Advisory 2025-11: CVE-2025-1020
Mozilla Foundation Security Advisory 2025-11
CVE: CVE-2025-1020
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 135
Mozilla
Mozilla Foundation Security Advisory 2025-07: CVE-2025-1020
vendor_mozilla·CVSS 9.8
CVE-2025-1020 [CRITICAL] Mozilla Foundation Security Advisory 2025-07: CVE-2025-1020
Mozilla Foundation Security Advisory 2025-07
CVE: CVE-2025-1020
Product: Firefox
Impact: high
Fixed in: Firefox 135
No detection rules found.
No public exploits indexed.
2025-02-04
Published