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Medium severity6.5NVD Advisory· Published Sep 1, 2026· Updated Sep 3, 2026

CVE-2026-84138

CVE-2026-84138

Description

Denial-of-service in the PDF Viewer component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

7

Mozilla Corporation/Firefoxllm-fuzzy
Range: >=155
Mozilla Corporation/Thunderbirdllm-fuzzy
Range: >=155
osv-coords5 versions
pkg:apk/chainguard/firefox pkg:apk/chainguard/firefox-docker-selenium-compat pkg:apk/wolfi/firefox pkg:apk/wolfi/firefox-docker-selenium-compat pkg:rpm/opensuse/MozillaFirefox&distro=openSUSE%20Tumbleweed
< 155.0.1-r0+ 4 more
- (no CPE)range: < 155.0.1-r0
- (no CPE)range: < 155.0.1-r0
- (no CPE)range: < 155.0.1-r0
- (no CPE)range: < 155.0.1-r0
- (no CPE)range: < 155.0-1.1

Patches

Vulnerability mechanics

References

3

www.mozilla.org/security/advisories/mfsa2026-82/nvdVendor Advisory
www.mozilla.org/security/advisories/mfsa2026-86/nvdVendor Advisory
bugzilla.mozilla.org/show_bug.cginvdIssue Tracking

News mentions

1

Mozilla Firefox & Thunderbird: 25 Vulnerabilities Including Critical Sandbox Escapes Disclosed Together
Vypr Intelligence · Sep 1, 2026