Medium 5.3Published Jun 11, 2018

CVE-2018-5121Low descenders on some Tibetan characters in several fonts on OS X are clipped when rendered in the addressbar.

Updated under an hour ago (Nov 2, 2026, 12:10 AM ET)

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It affects mozilla firefox. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Low descenders on some Tibetan characters in several fonts on OS X are clipped when rendered in the addressbar. When used as part of an Internationalized Domain Name (IDN) this can be used for domain name spoofing attacks. Note: This attack only affects OS X operating systems. Other operating systems are unaffected. This vulnerability affects Firefox < 58.

CVSS: 5.3 MEDIUM (v3.0, NVD)CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness (CWE): CWE-20
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Modified
Record last updated: Jun 16, 2026
First seen by InfoSec Signals: Nov 1, 2026

Affected products

Affected products

mozilla firefox mozilla:firefox	through 57.0.4	NVD

References

References

http://www.securityfocus.com/bid/102786	third-party-advisory, vdb-entry
http://www.securitytracker.com/id/1040270	third-party-advisory, vdb-entry
https://bugzilla.mozilla.org/show_bug.cgi?id=1402368	issue-tracking, permissions-required
https://www.mozilla.org/security/advisories/mfsa2018-02/	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.