A heap buffer overflow vulnerability may occur in WebAssembly when "shrinkElements" is called followed by garbage collection on memory that…

published 2018-06-11 8y ago modified 2026-06-17 4mo ago also EUVD-2018-16880

cvss: 7.5; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 15.0%; EPSS 15.0% chance of exploitation in 30 days, percentile 96%
public exploits: 0; none known

A heap buffer overflow vulnerability may occur in WebAssembly when "shrinkElements" is called followed by garbage collection on memory that is now uninitialized. This results in a potentially exploitable crash. This vulnerability affects Firefox < 58.

Patch / fix

fixed in 1 distros 2

Mozilla Firefox 58

ubuntu opensuse

firefox Ubuntu 14.04 LTS 58.0+build6-0ubuntu0.14.04.1
firefox Ubuntu 16.04 LTS 58.0+build6-0ubuntu0.16.04.1
firefox Ubuntu 18.04 LTS 59.0.1+build1-0ubuntu1

ubuntu advisories UBUNTU-CVE-2018-5094

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

firefox-esr openSUSE Tumbleweed 128.5.1-1.1
MozillaFirefox openSUSE Tumbleweed 92.0-1.2

opensuse advisories openSUSE-SU-2024:14572-1 openSUSE-SU-2024:10600-1

Is CVE-2018-5094 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Exploit prediction

14.96% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	3.0	7.5	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

Mozilla Firefox

Classification

Weakness

CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

usn.ubuntu.com /3544-1/
vendor-advisory, third-party-advisory
mozilla.org /security/advisories/mfsa2018-02/
vendor-advisory
securitytracker.com /id/1040270
vdb-entry, third-party-advisory
bugzilla.mozilla.org /show_bug.cgi?id=1415883
issue-tracking, permissions-required
securityfocus.com /bid/102786
vdb-entry, third-party-advisory

Sources

CVE List CVE-2018-5094
NVD CVE-2018-5094

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.