CVE-2019-9793
A mechanism was discovered that removes some bounds checking for string, array, or typed array accesses if Spectre mitigations have been…
- 5.9MediumCVSS base score
- 1.6%Exploitation in 30 daysEPSS · top 23% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
A mechanism was discovered that removes some bounds checking for string, array, or typed array accesses if Spectre mitigations have been disabled. This vulnerability could allow an attacker to create an arbitrary value in compiled JavaScript, for which the range analysis will infer a fully controlled, incorrect range in circumstances where users have explicitly disabled Spectre mitigations. *Note: Spectre mitigations are currently enabled for all users by default settings.*. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.
Timeline
ID reserved
By mozilla
- 43 days later
· 43 days later
Published
- 5 years later
· 5 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 | Medium5.9 | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N |
- EPSS (exploitation in 30 days)
- 1.6% · top 23% of all CVEs (11 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.
Affected products
- affected unspecified – < 60.6
- affected unspecified – < 60.6
- affected unspecified – < 66
References
References6
- https://www.mozilla.org/security/advisories/mfsa2019-07/ (opens in a new tab)x_refsource_MISCx_transferred
- https://www.mozilla.org/security/advisories/mfsa2019-08/ (opens in a new tab)x_refsource_MISCx_transferred
- https://www.mozilla.org/security/advisories/mfsa2019-11/ (opens in a new tab)x_refsource_MISCx_transferred
- https://bugzilla.mozilla.org/show_bug.cgi?id=1528829 (opens in a new tab)x_refsource_MISCx_transferred
- RHSA-2019:0966 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_transferred
- RHSA-2019:1144 (opens in a new tab)vendor-advisoryx_refsource_REDHATx_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-2019-19155 (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-2019-9793)Record last updated .