Information disclosure in the WebRTC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
CVE-2026-74958
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-18. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(high)
- EG Risk
- 49(Track)EG Risk 49/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 18%
- KEV
- Not listed
Published
August 18, 2026
Last Modified
August 19, 2026
Advisory Details (5)
Auto-updated Aug 18, 2026Security Vulnerabilities fixed in Thunderbird 153.1 — Mozilla
https://www.mozilla.org/security/advisories/mfsa2026-80/Security Vulnerabilities fixed in Thunderbird 154 — Mozilla
https://www.mozilla.org/security/advisories/mfsa2026-78/Security Vulnerabilities fixed in Firefox ESR 153.1 — Mozilla
https://www.mozilla.org/security/advisories/mfsa2026-77/Security Vulnerabilities fixed in Firefox 154 — Mozilla
https://www.mozilla.org/security/advisories/mfsa2026-74/Vendor Advisories for CVE-2026-74958(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 21× in last 7d / 21× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-21 03:20 UTCEG score recompute
- 2026-08-21 03:20 UTCGHSA enrichment
- 2026-08-20 22:56 UTCEPSS rescore
- 2026-08-20 14:47 UTCGHSA enrichment
- 2026-08-20 02:14 UTCEG score recompute
- 2026-08-20 02:14 UTCGHSA enrichment
- 2026-08-19 17:04 UTCEPSS rescore
- 2026-08-19 13:41 UTCGHSA enrichment
- 2026-08-19 01:08 UTCEG score recompute
- 2026-08-19 01:08 UTCGHSA enrichment
- 2026-08-18 20:24 UTCGHSA enrichment
- 2026-08-18 20:21 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
- 2026-08-18 19:23 UTCNVD update
- 2026-08-18 19:19 UTCEG score recompute▲ 7.50
- 2026-08-18 19:19 UTCGHSA enrichment
- 2026-08-18 19:18 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
- 2026-08-18 19:05 UTCGHSA enrichment
- 2026-08-18 19:04 UTCMITRE cvelistV5
- 2026-08-18 13:19 UTCNVD update
- 2026-08-18 12:42 UTCEG score recompute
- 2026-08-18 12:41 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-74958?
When was CVE-2026-74958 disclosed?
Is CVE-2026-74958 actively exploited?
What is the CVSS score of CVE-2026-74958?
How do I remediate CVE-2026-74958?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-74958
Is Your Infrastructure Affected by CVE-2026-74958?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.