CVE-2026-74968: mozilla firefox Origin Validation Error
CVSS: 5.4v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-74968CGA-cv78-m3pg-h98mCGA-h5xx-fxgj-6r2xCGA-hw8m-9rph-x98jCGA-j6fw-wmv9-wvg9CGA-29gp-m25x-j2fjCGA-fxw4-m2x2-28f2
Published 18-08-2026Last modified 18-08-2026
Vulnerability summary
CVE-2026-74968 is a medium (CVSS 5.4) Origin Validation Error vulnerability in mozilla firefox. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 4.5% of scored vulnerabilities.
CVSS score
5.4/10
010
Medium · v3.1 (CVE.org)EPSS score
0.16%
0%100%
Low · +0.05 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 13 · Related 12Timeline
- 18-08-2026PublishedVulnerability first disclosed.
- 18-08-2026Last modifiedVulnerability information updated.
Description
Site isolation issue in the Graphics: WebRender component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
CVSS metrics
3 scores · 3 sources · 1 versionMedium 5.4Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:NSourcesAll 3 agree
- OSV · UbuntuEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
- NVDNIST5.4MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
EPSS trend
Probability
0.16%
Chance of exploitation in the next 30 days
Percentile
5%
Versus all other CVEs
30-day change
+0.05 pp
From 0.10% on 20-09-2026
20-09-202620-10-2026
EPSS score0.16%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu8 products
- mozjs102All versions (No fix recorded)
- mozjs115All versions (No fix recorded)
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
Chainguard3 products
- firefox< 154.0-r0
- firefox-docker-selenium-compat< 154.0-r0
- firefox-esr-140< 140.14.0-r0
Mozilla2 products
- firefox< 153.1.0 | < 154.0.0
- thunderbird< 153.1.0 | < 154.0
Wolfi2 products
- firefox< 154.0-r0
- firefox-docker-selenium-compat< 154.0-r0
4 vendors · 15 products
References
8 links- bugzilla.mozilla.org/show_bug.cgi?id=2055738Permissions Required
- www.mozilla.org/security/advisories/mfsa2026-74/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-77/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-78/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-80/Vendor Advisory