CVE-2026-6767: mozilla firefox
CVSS: 5.3v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-6767DEBIAN-CVE-2026-6767CGA-8pfr-rr32-pfchCGA-9jpp-cp9h-7vhhCGA-23q9-7q5c-mc9pCGA-w3pg-623g-pvvq
Published 21-04-2026Last modified 27-05-2026
Vulnerability summary
CVE-2026-6767 is a medium (CVSS 5.3) vulnerability in mozilla firefox. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.8% of scored vulnerabilities.
CVSS score
5.3/10
010
Medium · v3.1 (CVE.org)EPSS score
0.38%
0%100%
Low · +0.15 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 30 · Related 4OPENSUSE-SU-2026:10610-1OPENSUSE-SU-2026:10626-1OPENSUSE-SU-2026:11373-1RHSA-2026:10757RHSA-2026:10766RHSA-2026:10767RHSA-2026:12285RHSA-2026:13537RHSA-2026:15892RHSA-2026:17477RHSA-2026:17687RHSA-2026:17688RHSA-2026:17689RHSA-2026:17690RHSA-2026:19041RHSA-2026:19131RHSA-2026:19201RHSA-2026:19348RHSA-2026:19461RHSA-2026:19462RHSA-2026:19463RHSA-2026:19464RHSA-2026:19465RHSA-2026:19466RHSA-2026:19467RHSA-2026:19468RHSA-2026:19469RHSA-2026:19542RHSA-2026:19655RHSA-2026:19704CGA-RP24-M6QC-6PMW
Timeline
- 21-04-2026PublishedVulnerability first disclosed.
- 27-05-2026Last modifiedVulnerability information updated.
Description
Other issue in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
CVSS metrics
4 scores · 4 sources · 1 versionMedium 5.3Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NSourcesAll 4 agree
- OSV · UbuntuEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- OSV · DebianEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- NVDNIST5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.38%
Chance of exploitation in the next 30 days
Percentile
31%
Versus all other CVEs
30-day change
+0.15 pp
From 0.23% on 21-09-2026
21-09-202621-10-2026
EPSS score0.38%
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)
Debian3 products
- firefox-esr< 140.10.0esr-1~deb12u1 | < 140.10.0esr-1~deb13u1 | < 140.10.0esr-1
- nss< 2:3.87.1-1+deb12u3 | < 2:3.110-1+deb13u2 | < 2:3.123-1
- thunderbird< 1:140.10.0esr-1~deb12u1 | < 1:140.10.0esr-1~deb13u1 | < 1:140.10.0esr-1
Chainguard2 products
- firefox< 140.10-r0
- firefox-esr< 140.10-r0
Mozilla2 products
- firefox< 115.35.0 | < 150.0 | ≥ 140.0, < 140.10.0
- thunderbird≥ 140.0, < 140.10.0
Wolfi1 product
- firefox< 140.10-r0
5 vendors · 16 products
References
11 links- bugzilla.mozilla.org/show_bug.cgi?id=2023209Permissions Required
- www.mozilla.org/security/advisories/mfsa2026-30/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-31/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-32/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-33/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-34/Vendor Advisory
