CVE-2020-13962

Exp

Qt 5.12.2 through 5.14.2, as used in unofficial builds of Mumble 1.3.0 and other products, mishandles OpenSSL's error queue, which can cause a denial of service to QSslSocket users. Because errors leak in unrelated TLS sessions, an unrelated session may be disconnected when any handshake fails. (Mumble 1.3.1 is not affected, regardless of the Qt version.)

Published: 2020-06-08 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-13962 is rated High Exploit Risk (75.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.01%). 1 public exploit reference(s) are indexed (Exploit-DB). 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-2020-13962

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-13962

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 2026-06-18 2.93% 3.01% +0.08%
2 2026-06-15 1.57% 2.93% +1.36%
3 2025-12-28 — 1.57% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-13962

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-13962

OS Trackers for CVE-2020-13962

vendor priority summary link
debian not yet assigned CVE-2020-13962 not yet assigned priority: Debian including 1 source packages (qtbase-opensource-src), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-13962
gentoo normal CVE-2020-13962: 1 GLSA(s) (202007-18), 1 atom(s) (dev-qt/qtnetwork); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-13962
redhat medium — https://access.redhat.com/security/cve/CVE-2020-13962
suse high — https://www.suse.com/security/cve/CVE-2020-13962/
ubuntu medium CVE-2020-13962 medium priority: Ubuntu including 1 source packages (qtbase-opensource-src), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 13, released 2, DNE 1, ignored 1. https://ubuntu.com/security/CVE-2020-13962

Affected software / configurations for CVE-2020-13962

Vendor Product Version Raw CPE
mumble mumble 1.3.0 cpe:2.3:a:mumble:mumble:1.3.0:-:*:*:*:*:*:*
qt qt >= 5.12.2, < 5.12.9 cpe:2.3:a:qt:qt:*:*:*:*:*:*:*:*
qt qt >= 5.13.0, <= 5.13.2 cpe:2.3:a:qt:qt:*:*:*:*:*:*:*:*
qt qt >= 5.14.0, <= 5.14.2 cpe:2.3:a:qt:qt:*:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
opensuse leap 15.2 cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*

References for CVE-2020-13962

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00004.html Mailing List Third Party Advisory
https://bugreports.qt.io/browse/QTBUG-83450 Issue Tracking Vendor Advisory
https://github.com/mumble-voip/mumble/issues/3679 Exploit Issue Tracking Patch Third Party Advisory
https://github.com/mumble-voip/mumble/pull/4032 Patch Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4X6EDPIIAQPVP2CHL2CHDHJ25EECA7UE/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UQJDBZUYMMF4R5QQKD2HTIKQU2NSKO63/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V3IZY7LKJ6NAXQDFYFR4S7L5BBHYK53K/
https://security.gentoo.org/glsa/202007-18 Third Party Advisory
cvelogic Threat Intelligence