CVE-2018-18494

CVE-2018-18494 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-346.

Key facts

• Severity: Medium (CVSS 3.x base score 6.5)
• CVSS v2: 4.3
• EPSS exploit prediction: 2% (72nd percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-346
• Affected product: Mozilla Firefox
• Published: 2019-02-28
• Last modified: 2026-06-17

Description

A same-origin policy violation allowing the theft of cross-origin URL entries when using the Javascript location property to cause a redirection to another site using performance.getEntries(). This is a same-origin policy violation and could allow for data theft. This vulnerability affects Thunderbird < 60.4, Firefox ESR < 60.4, and Firefox < 64.

Frequently asked questions

What is CVE-2018-18494?

A same-origin policy violation allowing the theft of cross-origin URL entries when using the Javascript location property to cause a redirection to another site using performance.getEntries(). This is a same-origin policy violation and could allow for data theft. This vulnerability affects Thunderbird < 60.4, Firefox ESR < 60.4, and Firefox < 64.

How severe is CVE-2018-18494?

CVE-2018-18494 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2018-18494 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-18494?

CVE-2018-18494 primarily affects Mozilla Firefox. In total, 17 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-18494?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-18494 published?

CVE-2018-18494 was published on 2019-02-28 and last updated on 2026-06-17.

References

• http://www.securityfocus.com/bid/106168
• https://access.redhat.com/errata/RHSA-2018:3831
• https://access.redhat.com/errata/RHSA-2018:3833
• https://access.redhat.com/errata/RHSA-2019:0159
• https://access.redhat.com/errata/RHSA-2019:0160
• https://bugzilla.mozilla.org/show_bug.cgi?id=1487964
• https://lists.debian.org/debian-lts-announce/2018/12/msg00002.html
• https://security.gentoo.org/glsa/201903-04
• https://usn.ubuntu.com/3844-1/
• https://usn.ubuntu.com/3868-1/
• https://www.debian.org/security/2018/dsa-4354
• https://www.debian.org/security/2019/dsa-4362
• https://www.mozilla.org/security/advisories/mfsa2018-29/
• https://www.mozilla.org/security/advisories/mfsa2018-30/
• https://www.mozilla.org/security/advisories/mfsa2018-31/

Affected products (17)

• cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
• cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
• cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_eus:7.6:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:*
• cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*

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