CVE-2026-12327
published 2026-06-16CVE-2026-12327: Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151. Some of these bugs showed evidence of memory…
PriorityP345high7.3CVSS 3.1
AVNACLPRNUINSUCLILAL
EPSS
0.41%
32.8th percentile
Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151. 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 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.
Affected
8 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 152 | Firefox 152 |
| mozilla | firefox | — | — |
| mozilla | firefox_esr | < Firefox ESR 140.12 | Firefox ESR 140.12 |
| mozilla | thunderbird | < Thunderbird 152 | Thunderbird 152 |
| mozilla | thunderbird | < Thunderbird 140.12 | Thunderbird 140.12 |
| mozilla | thunderbird | — | — |
| rhel10 | firefox-flatpak | — | — |
| rhel10 | thunderbird-flatpak | — | — |
CVSS provenance
nvdv3.17.3HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
vendor_redhat7.3HIGH
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Red Hat
firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152
vendor_redhat·2026-06-16·CVSS 7.3
CVE-2026-12327 [HIGH] CWE-787 firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152
firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152
Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151. 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 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151. Some of these bugs showed evidence of memory corruption and we presume that
Mozilla
Mozilla Foundation Security Advisory 2026-60: CVE-2026-12327
vendor_mozilla·CVSS 7.3
CVE-2026-12327 [HIGH] Mozilla Foundation Security Advisory 2026-60: CVE-2026-12327
Mozilla Foundation Security Advisory 2026-60
CVE: CVE-2026-12327
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 152
Mozilla
Mozilla Foundation Security Advisory 2026-57: CVE-2026-12327
vendor_mozilla·CVSS 7.3
CVE-2026-12327 [HIGH] Mozilla Foundation Security Advisory 2026-57: CVE-2026-12327
Mozilla Foundation Security Advisory 2026-57
CVE: CVE-2026-12327
Product: Firefox
Impact: high
Fixed in: Firefox 152
Mozilla
Mozilla Foundation Security Advisory 2026-61: CVE-2026-12327
vendor_mozilla·CVSS 7.3
CVE-2026-12327 [HIGH] Mozilla Foundation Security Advisory 2026-61: CVE-2026-12327
Mozilla Foundation Security Advisory 2026-61
CVE: CVE-2026-12327
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 140.12
Mozilla
Mozilla Foundation Security Advisory 2026-58: CVE-2026-12327
vendor_mozilla·CVSS 7.3
CVE-2026-12327 [HIGH] Mozilla Foundation Security Advisory 2026-58: CVE-2026-12327
Mozilla Foundation Security Advisory 2026-58
CVE: CVE-2026-12327
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 140.12
VulDB
Mozilla Firefox up to 151 memory corruption (Nessus ID 321490 / WID-SEC-2026-1959)
vuldb·2026-07-10·CVSS 7.3
CVE-2026-12327 [HIGH] Mozilla Firefox up to 151 memory corruption (Nessus ID 321490 / WID-SEC-2026-1959)
A vulnerability, which was classified as critical, was found in Mozilla Firefox up to 151. Impacted is an unknown function. The manipulation results in memory corruption.
This vulnerability is known as CVE-2026-12327. It is possible to launch the attack remotely. No exploit is available.
You should upgrade the affected component.
GHSA
Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151.
ghsa_unreviewed·2026-06-16
CVE-2026-12327 [HIGH] CWE-119 Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151.
Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151. 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 152 and Firefox ESR 140.12.
No detection rules found.
No public exploits indexed.
Hackernews
⚡ Weekly Recap: Browser Bugs, EDR Killers, TV Botnet, OpenBSD Flaw, Android Trojan, and More
blogs_hackernews·2026-06-22·CVSS 9.8
CVE-2026-24858 [CRITICAL] ⚡ Weekly Recap: Browser Bugs, EDR Killers, TV Botnet, OpenBSD Flaw, Android Trojan, and More
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## ⚡ Weekly Recap: Browser Bugs, EDR Killers, TV Botnet, OpenBSD Flaw, Android Trojan, and More
It’s Monday again.
This week’s threat list looks painfully familiar: abused integrations, fake tools, poisoned websites, ransomware crews trying to shut down security tools, and mobile malware asking for way too much control.
The annoying part is how little of this feels new. Weak credentials, sketchy downloads, browser extensions with too much access, and WordPress sites are used to push more attacks. Nothing clever. Just sloppy, cheap, and effective.
Here’s the Monday recap. Let’s get into the week’s mess.
## ⚡ Threat of the We
Bugzilla
CVE-2026-12327 firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152
bugzilla·2026-06-16·CVSS 7.3
CVE-2026-12327 [HIGH] CVE-2026-12327 firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152
CVE-2026-12327 firefox: thunderbird: Memory safety bugs fixed in Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152
Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, Firefox 151 and Thunderbird 151. 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 152 and Firefox ESR 140.12.
https://bugzilla.mozilla.org/buglist.cgi?bug_id=2011842%2C2023902%2C2025512%2C2027312%2C2029444%2C2036571%2C2036900%2C2036936%2C2037995%2C2038551%2C2040717%2C2042724https://www.mozilla.org/security/advisories/mfsa2026-57/https://www.mozilla.org/security/advisories/mfsa2026-58/https://www.mozilla.org/security/advisories/mfsa2026-60/https://www.mozilla.org/security/advisories/mfsa2026-61/
2026-06-16
Published