No exploitation reportedFix available

CVE-2017-7749

Q: Is CVE-2017-7749 actively exploited?

Active exploitation of CVE-2017-7749 has not been confirmed. Its EPSS score was 2.6% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2017-7749?

CVE-2017-7749 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2018-06-11
WeaknessCWE-416

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A use-after-free vulnerability when using an incorrect URL during the reloading of a docshell. This results in a potentially exploitable crash. This vulnerability affects Firefox < 54, Firefox ESR < 52.2, and Thunderbird < 52.2.

Timeline

dates in UTC

2018-06-1121:29CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2017-7749?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2017-7749?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Redhat enterprise linux server eus

Branch	Affected	Fixed in	Source
7.3	= 7.3	no fix published	NVD
7.4	= 7.4	no fix published	NVD
7.5	= 7.5	no fix published	NVD

Debian debian linux

Branch	Affected	Fixed in	Source
8.0	= 8.0	no fix published	NVD
9.0	= 9.0	no fix published	NVD

Mozilla firefox

Branch	Affected	Fixed in	Source
54.0	< 54.0	54.0	NVD
52.2	< 52.2.0	52.2.0	NVD

6 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

bugzilla.mozilla.orgPatch · Vendor Advisory
www.mozilla.orgVendor Advisory
www.mozilla.orgVendor Advisory
www.mozilla.orgVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.09.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-416read 2026-10-23
FIRST EPSSEPSS score2.6 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2018-06-11
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2017-7749?

Is CVE-2017-7749 actively exploited?

Active exploitation of CVE-2017-7749 has not been confirmed. Its EPSS score was 2.6% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2017-7749?

CVE-2017-7749 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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