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Fencer Vulns
high 8.8

CVE-2026-74955 json

Privilege escalation in the Request Handling component

published 2026-08-18 2 mo ago modified 2026-08-21 2 mo ago also EUVD-2026-60682

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits
0
none known

Summary

Privilege escalation in the Request Handling component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

Patch / fix

  • mozilla firefox 153.1.0, 154.0.0
  • mozilla thunderbird 153.1.0, 154.0
  • MozillaThunderbird SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 153.2.0-150400.13.3.1
  • mozilla-nss SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +11 more 3.125-150400.3.74.1
  • mozilla-nspr SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +11 more 4.39-150400.12.3.1
  • MozillaFirefox SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 153.2.0-150400.157.5.1
  • MozillaFirefox-branding-SLE SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 153-150400.14.3.1
  • mozilla-nss SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 3.125-160000.1.1
  • mozilla-nspr SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 4.39-160000.1.1
  • rust-cbindgen SLES for SAP applications 16.0, SLES 16.0 0.29.4+git0-160000.1.1

suse advisories SUSE-SU-2026:4268-1SUSE-SU-2026:4156-1SUSE-SU-2026:4140-1SUSE-SU-2026:23411-1SUSE-SU-2026:23590-1SUSE-SU-2026:3683-1

  • MozillaThunderbird openSUSE Tumbleweed 153.4.0-1.1
  • rust-cbindgen openSUSE Leap 16.0 0.29.4+git0-160000.1.1
  • mozilla-nss openSUSE Leap 16.0 3.125-160000.1.1
  • mozilla-nspr openSUSE Leap 16.0 4.39-160000.1.1
  • MozillaFirefox openSUSE Leap 16.0 153.1.0-160000.1.2
  • MozillaFirefox openSUSE Tumbleweed 154.0-1.1
  • firefox-esr openSUSE Tumbleweed 153.1.0-1.1

opensuse advisories openSUSE-SU-2026:12098-1openSUSE-SU-2026:21713-1openSUSE-SU-2026:11580-1openSUSE-SU-2026:11546-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-74955 updated cvss 6.1

firefox: thunderbird: Privilege escalation in the Request Handling component

  • Red Hat Enterprise Linux 6 firefox, thunderbird Red Hat Enterprise Linux 7 firefox, thunderbird Red Hat Enterprise Linux 8 firefox, thunderbird Red Hat Enterprise Linux 9 firefox, firefox-x11, thunderbird Red Hat Enterprise Linux 10 firefox, thunderbird, rhel10/firefox-flatpak, rhel10/thunderbird-flatpak
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2 mo ago

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

  • Mozilla Firefox
  • Mozilla Thunderbird

Classification

Weakness
  • CWE-269 Improper Privilege Management

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.