CVE-2018-5092
A use-after-free vulnerability can occur when the thread for a Web Worker is freed from memory prematurely instead of from memory in the main thread while cancelling fetch operations.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.78%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A use-after-free vulnerability can occur when the thread for a Web Worker is freed from memory prematurely instead of from memory in the main thread while cancelling fetch operations. This vulnerability affects Firefox < 58.
- CVSS 3.0
- 9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.78% probability · 78th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- mozilla/firefox · canonical/ubuntu linux
- Source
- security@mozilla.org
EPSS 1.8% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/102786Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1040270Third Party Advisory, VDB Entry
- https://bugzilla.mozilla.org/show_bug.cgi?id=1418074Issue Tracking, Permissions Required
- https://usn.ubuntu.com/3544-1/Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2018-02/Vendor Advisory
- http://www.securityfocus.com/bid/102786Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1040270Third Party Advisory, VDB Entry
- https://bugzilla.mozilla.org/show_bug.cgi?id=1418074Issue Tracking, Permissions Required
- https://usn.ubuntu.com/3544-1/Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2018-02/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.