CVE-2026-74988
published 2026-08-18CVE-2026-74988: Internally found bugs present in Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another…
PriorityP351critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.35%
28.2th percentile
Internally found bugs present in Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
Affected
6 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 154 | Firefox 154 |
| mozilla | firefox | < 153.1.0 | 153.1.0 |
| mozilla | firefox_esr | < Firefox ESR 153.1 | Firefox ESR 153.1 |
| mozilla | thunderbird | < Thunderbird 153.1 | Thunderbird 153.1 |
| mozilla | thunderbird | < Thunderbird 154 | Thunderbird 154 |
| mozilla | thunderbird | < 153.1.0 | 153.1.0 |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vendor_redhat9.8CRITICAL
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Red Hat
firefox: thunderbird: Internally found bugs fixed in Firefox ESR 153.1 and Firefox 154
vendor_redhat·2026-08-18·CVSS 9.8
CVE-2026-74988 [CRITICAL] CWE-130 firefox: thunderbird: Internally found bugs fixed in Firefox ESR 153.1 and Firefox 154
firefox: thunderbird: Internally found bugs fixed in Firefox ESR 153.1 and Firefox 154
A flaw was found in Firefox and Thunderbird. The Mozilla Foundation's Security Advisory describes the following issue:
Internally found bugs present in Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited.
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 aff
Mozilla
Mozilla Foundation Security Advisory 2026-74: CVE-2026-74988
vendor_mozilla
CVE-2026-74988 Mozilla Foundation Security Advisory 2026-74: CVE-2026-74988
Mozilla Foundation Security Advisory 2026-74
CVE: CVE-2026-74988
Product: Firefox
Impact: high
Fixed in: Firefox 154
Mozilla
Mozilla Foundation Security Advisory 2026-77: CVE-2026-74988
vendor_mozilla
CVE-2026-74988 Mozilla Foundation Security Advisory 2026-77: CVE-2026-74988
Mozilla Foundation Security Advisory 2026-77
CVE: CVE-2026-74988
Product: Firefox ESR
Impact: high
Fixed in: Firefox ESR 153.1
Mozilla
Mozilla Foundation Security Advisory 2026-80: CVE-2026-74988
vendor_mozilla
CVE-2026-74988 Mozilla Foundation Security Advisory 2026-80: CVE-2026-74988
Mozilla Foundation Security Advisory 2026-80
CVE: CVE-2026-74988
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 153.1
Mozilla
Mozilla Foundation Security Advisory 2026-78: CVE-2026-74988
vendor_mozilla
CVE-2026-74988 Mozilla Foundation Security Advisory 2026-78: CVE-2026-74988
Mozilla Foundation Security Advisory 2026-78
CVE: CVE-2026-74988
Product: Thunderbird
Impact: high
Fixed in: Thunderbird 154
GHSA
Internally found bugs present in Firefox ESR 153.0 and Firefox 153.
ghsa_unreviewed·2026-08-18
CVE-2026-74988 Internally found bugs present in Firefox ESR 153.0 and Firefox 153.
Internally found bugs present in Firefox ESR 153.0 and Firefox 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154 and Firefox ESR 153.1.
No detection rules found.
No public exploits indexed.
https://bugzilla.mozilla.org/buglist.cgi?bug_id=2018164%2C2045404%2C2045507%2C2045711%2C2052403%2C2053174%2C2054643%2C2054667%2C2054671%2C2054674%2C2054687%2C2054717%2C2054761%2C2054787%2C2055676%2C2056779%2C2056781%2C2058629%2C2059019%2C2059138https://bugzilla.mozilla.org/buglist.cgi?bug_id=2045796%2C2046734%2C2051424%2C2054721%2C2057994%2C2058094%2C2058611%2C2058615%2C2058616%2C2061315https://bugzilla.mozilla.org/buglist.cgi?bug_id=2053153%2C2053262%2C2054763%2C2059198%2C2059224https://www.mozilla.org/security/advisories/mfsa2026-74/https://www.mozilla.org/security/advisories/mfsa2026-77/https://www.mozilla.org/security/advisories/mfsa2026-78/https://www.mozilla.org/security/advisories/mfsa2026-80/
2026-08-18
Published