CVE-2016-1960

Exp

Integer underflow in the nsHtml5TreeBuilder class in the HTML5 string parser in Mozilla Firefox before 45.0 and Firefox ESR 38.x before 38.7 allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free) by leveraging mishandling of end tags, as demonstrated by incorrect SVG processing, aka ZDI-CAN-3545.

Published: 2016-03-13 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2016-1960 is rated High Exploit Risk (84.4/100): CVSS High severity, with high exploitation likelihood (EPSS 86.45%, 99th percentile). Core evidence: 2 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2016-1960

EDB-ID Source Kind Published Link
44294 exploit_db edb 2018-03-16 Exploit-DB ↗
42484 exploit_db edb 2017-08-18 Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2016-1960

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-05 87.06% 86.45% -0.60%
2 2026-03-02 86.70% 87.06% +0.36%
3 2026-02-18 86.70%

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-1960

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
8.6 6.4 [email protected]

Weakness enumeration for CVE-2016-1960

OS Trackers for CVE-2016-1960

vendor priority summary link
debian not yet assigned CVE-2016-1960 not yet assigned priority: Debian including 2 source packages (firefox, firefox-esr), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2016-1960
gentoo normal CVE-2016-1960: 1 GLSA(s) (201605-06), 6 atom(s) (dev-libs/nspr, dev-libs/nss, mail-client/thunderbird, mail-client/thunderbird-bin, www-client/firefox, www-client/firefox-bin); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-1960
redhat critical https://access.redhat.com/security/cve/CVE-2016-1960
suse high CVE-2016-1960 severity important: SUSE including 151 source package names (MozillaFirefox-102.11.0-150200.152.87.1, MozillaFirefox-115.10.0-150200.152.134.1, …), 389 product×package rows across 71 product lines (Image SLES12-SP5-Azure-BYOS, Image SLES12-SP5-Azure-Basic-On-Demand, … (71 product lines)): Fixed 389. https://www.suse.com/security/cve/CVE-2016-1960/
ubuntu medium CVE-2016-1960 medium priority: Ubuntu including 2 source packages (firefox, thunderbird), 10 status rows across 5 suites (precise, trusty, upstream, wily, xenial): released 9, not-affected 1. https://ubuntu.com/security/CVE-2016-1960

NVD evaluator notes for CVE-2016-1960

Comment: <a href="http://cwe.mitre.org/data/definitions/416.html">CWE-416: Use After Free</a>

Affected software / configurations for CVE-2016-1960

Vendor Product Version Raw CPE
oracle linux 5.0 cpe:2.3:o:oracle:linux:5.0:*:*:*:*:*:*:*
oracle linux 6 cpe:2.3:o:oracle:linux:6:*:*:*:*:*:*:*
oracle linux 7 cpe:2.3:o:oracle:linux:7:*:*:*:*:*:*:*
mozilla firefox <= 44.0.2 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla firefox 38.0 cpe:2.3:a:mozilla:firefox:38.0:*:*:*:*:*:*:*
mozilla firefox 38.0.1 cpe:2.3:a:mozilla:firefox:38.0.1:*:*:*:*:*:*:*
mozilla firefox 38.0.5 cpe:2.3:a:mozilla:firefox:38.0.5:*:*:*:*:*:*:*
mozilla firefox 38.1.0 cpe:2.3:a:mozilla:firefox:38.1.0:*:*:*:*:*:*:*
mozilla firefox 38.1.1 cpe:2.3:a:mozilla:firefox:38.1.1:*:*:*:*:*:*:*
mozilla firefox 38.2.0 cpe:2.3:a:mozilla:firefox:38.2.0:*:*:*:*:*:*:*
mozilla firefox 38.2.1 cpe:2.3:a:mozilla:firefox:38.2.1:*:*:*:*:*:*:*
mozilla firefox 38.3.0 cpe:2.3:a:mozilla:firefox:38.3.0:*:*:*:*:*:*:*
mozilla firefox 38.4.0 cpe:2.3:a:mozilla:firefox:38.4.0:*:*:*:*:*:*:*
mozilla firefox 38.5.0 cpe:2.3:a:mozilla:firefox:38.5.0:*:*:*:*:*:*:*
mozilla firefox 38.5.1 cpe:2.3:a:mozilla:firefox:38.5.1:*:*:*:*:*:*:*
mozilla firefox 38.6.0 cpe:2.3:a:mozilla:firefox:38.6.0:*:*:*:*:*:*:*
mozilla firefox 38.6.1 cpe:2.3:a:mozilla:firefox:38.6.1:*:*:*:*:*:*:*
mozilla thunderbird <= 38.6.0 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
opensuse leap 42.1 cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:*
opensuse opensuse 13.1 cpe:2.3:o:opensuse:opensuse:13.1:*:*:*:*:*:*:*
opensuse opensuse 13.2 cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:*
suse linux_enterprise 12.0 cpe:2.3:o:suse:linux_enterprise:12.0:*:*:*:*:*:*:*

References for CVE-2016-1960

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00027.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00029.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00031.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00050.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00068.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00089.html
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00091.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00093.html
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00006.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00007.html Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2016-07/msg00008.html Third Party Advisory
http://www.debian.org/security/2016/dsa-3510
http://www.debian.org/security/2016/dsa-3520
http://www.mozilla.org/security/announce/2016/mfsa2016-23.html Vendor Advisory
http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html Third Party Advisory
http://www.securitytracker.com/id/1035215
http://www.ubuntu.com/usn/USN-2917-1
http://www.ubuntu.com/usn/USN-2917-2
http://www.ubuntu.com/usn/USN-2917-3
http://www.ubuntu.com/usn/USN-2934-1
http://zerodayinitiative.com/advisories/ZDI-16-198/ Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1246014 Issue Tracking
https://security.gentoo.org/glsa/201605-06
https://www.exploit-db.com/exploits/42484/
https://www.exploit-db.com/exploits/44294/
cvelogic Threat Intelligence