CVE-2025-4082: mozilla firefox Out-of-bounds Read
Vulnerability summary
CVE-2025-4082 is a medium (CVSS 5.9) Out-of-bounds Read vulnerability in mozilla firefox. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 37.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 5 · Related 7Timeline
- 29-04-2025PublishedVulnerability first disclosed.
- 13-04-2026Last modifiedVulnerability information updated.
Description
Modification of specific WebGL shader attributes could trigger an out-of-bounds read, which, when chained with other vulnerabilities, could be used to escalate privileges. *This bug only affects Thunderbird for macOS. Other versions of Thunderbird are unaffected.*. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Firefox ESR 115.23, Thunderbird 138, and Thunderbird 128.10.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.45%
Chance of exploitation in the next 30 days
Percentile
38%
Versus all other CVEs
30-day change
+0.02 pp
From 0.43% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Chainguard2 products
- firefox< 128.10-r0
- firefox-esr< 115.23-r0
Mozilla2 products
- firefox< 115.23 | < 138.0 | ≥ 128.0, < 128.10
- thunderbird< 128.10.0 | < 138.0
Wolfi1 product
- firefox< 128.10-r0
3 vendors · 5 products
References
7 links- bugzilla.mozilla.org/show_bug.cgi?id=1937097Permissions Required
- www.mozilla.org/security/advisories/mfsa2025-28/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-29/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-30/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-31/Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2025-32/Vendor Advisory
