CVE-2018-5143
URLs using "javascript:" have the protocol removed when pasted into the addressbar to protect users from cross-site scripting (XSS)…
- 6.1MediumCVSS base score
- 0.92%Exploitation in 30 daysEPSS · top 39% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
URLs using "javascript:" have the protocol removed when pasted into the addressbar to protect users from cross-site scripting (XSS) attacks, but if a tab character is embedded in the "javascript:" URL the protocol is not removed and the script will execute. This could allow users to be socially engineered to run an XSS attack against themselves. This vulnerability affects Firefox < 59.
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 | Medium6.1 | CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.92% · top 39% of all CVEs (10 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.1.
Affected products
References
5
- https://bugzilla.mozilla.org/show_bug.cgi?id=1422643 (opens in a new tab)x_refsource_CONFIRMx_transferred
- 103386 (opens in a new tab)vdb-entryx_refsource_BIDx_transferred
- 1040514 (opens in a new tab)vdb-entryx_refsource_SECTRACKx_transferred
- USN-3596-1 (opens in a new tab)vendor-advisoryx_refsource_UBUNTUx_transferred
- https://www.mozilla.org/security/advisories/mfsa2018-06/ (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-2018-16929 (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-2018-5143)Record last updated .