CVE-2018-5116
WebExtensions with the "ActiveTab" permission are able to access frames hosted within the active tab even if the frames are cross-origin.…
- 9.8CriticalCVSS base score
- 1.1%Exploitation in 30 daysEPSS · top 33% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
WebExtensions with the "ActiveTab" permission are able to access frames hosted within the active tab even if the frames are cross-origin. Malicious extensions can inject frames from arbitrary origins into the loaded page and then interact with them, bypassing same-origin user expectations with this permission. This vulnerability affects Firefox < 58.
Timeline
ID reserved
By mozilla
- 5 months later
· 5 months later
Published
- 6 years later
· 6 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.0 | Critical9.8 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.1% · top 33% of all CVEs (9 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
References
5
- 1040270 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- https://bugzilla.mozilla.org/show_bug.cgi?id=1396399 (opens in a new tab)x_refsource_CONFIRMx_transferred
- USN-3544-1 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- 102786 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- https://www.mozilla.org/security/advisories/mfsa2018-02/ (opens in a new tab)x_refsource_CONFIRMx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2018-16902 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2018-5116)Record last updated .