Vulnerability record

CVE-2015-4495

Mozilla Firefox Security Feature Bypass Vulnerability

HighExploitation confirmedCISA KEV

What should I do?

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run Firefox, fix it now.

CISA required action: Apply updates per vendor instructions.

US federal civilian agencies must remediate by Jun 15, 2022.

Patch status

Official fix available since Sep 30, 2026

Apply the vendor's update to every affected system. Check the fixed-in versions below where known.

Basis: NVD patch reference

Patch or advisory on oracle.com (opens in a new tab)

Description

The PDF reader in Mozilla Firefox before 39.0.3, Firefox ESR 38.x before 38.1.1, and Firefox OS before 2.2 allows remote attackers to bypass the Same Origin Policy, and read arbitrary files or gain privileges, via vectors involving crafted JavaScript code and a native setter, as exploited in the wild in August 2015.

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Affected products

Products affected by this vulnerability, with versions and the source of each entry
Product	Vendor	Affected versions	Fixed in	Source
Firefox	Mozilla	< 39.0.3; >= 38.0, < 38.1.1	39.0.3; 38.1.1	KEV
Solaris	Oracle	11.3	—	NVD

Sources: KEV = CISA Known Exploited Vulnerabilities catalog; NVD = NIST National Vulnerability Database.

Intelligence timeline

Developments from the last 30 days, newest first.

CVSS scoredUpdateKEVSep 30, 2026
CVE-2015-4495 scored CVSS 8.8: Mozilla Firefox, Mozilla Firefox Security Feature Bypass Vulnerability
CISA lists this as exploited in the wild. Unpatched Firefox systems are exposed to active attacks now.
Basis: NIST National Vulnerability Database
Patch releasedUpdateKEVSep 30, 2026
Patch released for CVE-2015-4495: Mozilla Firefox, Mozilla Firefox Security Feature Bypass Vulnerability
An official fix is now available for Mozilla Firefox. This vulnerability is being exploited, so apply it promptly.
Basis: NVD patch reference

1 earlier event is available with a subscription. See plans.

Coverage

We have not published a story about this vulnerability yet.

References

nvd.nist.gov https://nvd.nist.gov/vuln/detail/CVE-2015-4495
lists.opensuse.org http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00009.html
lists.opensuse.org http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00010.html
lists.opensuse.org http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00014.html
lists.opensuse.org http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00015.html
lists.opensuse.org http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00021.html
lists.opensuse.org http://lists.opensuse.org/opensuse-security-announce/2015-09/msg00016.html
rhn.redhat.com http://rhn.redhat.com/errata/RHSA-2015-1581.html
mozilla.org http://www.mozilla.org/security/announce/2015/mfsa2015-78.html
oracle.com http://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
securityfocus.com http://www.securityfocus.com/bid/76249
securitytracker.com http://www.securitytracker.com/id/1033216
ubuntu.com http://www.ubuntu.com/usn/USN-2707-1
blog.mozilla.org https://blog.mozilla.org/security/2015/08/06/firefox-exploit-found-in-the-wild/
bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1178058
bugzilla.mozilla.org https://bugzilla.mozilla.org/show_bug.cgi?id=1179262
security.gentoo.org https://security.gentoo.org/glsa/201512-10
exploit-db.com https://www.exploit-db.com/exploits/37772/
cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2015-4495