CVE-2020-26421

Exp

Crash in USB HID protocol dissector and possibly other dissectors in Wireshark 3.4.0 and 3.2.0 to 3.2.8 allows denial of service via packet injection or crafted capture file.

Published: 2020-12-11 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-26421 is rated High Exploit Risk (63.4/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.59%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +2.49% over the last day, indicating growing attacker interest. 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-2020-26421

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

Exploit prediction scoring system (EPSS) score for CVE-2020-26421

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 2026-06-15 0.10% 2.59% +2.49%
2 2025-11-21 0.81% 0.10% -0.71%
3 2025-11-18 — 0.81% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-26421

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.2 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:L 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 1.6 2.5 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L 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:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [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-2020-26421

OS Trackers for CVE-2020-26421

vendor priority summary link
alpine medium CVE-2020-26421: 1 source package rows (wireshark); 21 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 14. https://security.alpinelinux.org/vuln/CVE-2020-26421
debian not yet assigned CVE-2020-26421 not yet assigned priority: Debian including 1 source packages (wireshark), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-26421
gentoo normal CVE-2020-26421: 1 GLSA(s) (202101-12), 1 atom(s) (net-analyzer/wireshark); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-26421
redhat low — https://access.redhat.com/security/cve/CVE-2020-26421
suse medium CVE-2020-26421 severity moderate: SUSE including 98 source package names (libQt5Multimedia5-5.9.7-7.2.1, libqt5-qtmultimedia-devel-5.9.7-7.2.1, …), 440 product×package rows across 64 product lines (Image SLES12-SP5-SAP-Azure-LI-BYOS-Production, Image SLES12-SP5-SAP-Azure-VLI-BYOS-Production, … (64 product lines)): Fixed 419, Will Not Fix 12, Known Not Affected 9. https://www.suse.com/security/cve/CVE-2020-26421/
ubuntu medium CVE-2020-26421 medium priority: Ubuntu including 1 source packages (wireshark), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 10, needed 4, ignored 1, released 1. https://ubuntu.com/security/CVE-2020-26421

Affected software / configurations for CVE-2020-26421

Vendor Product Version Raw CPE
wireshark wireshark >= 3.2.0, <= 3.2.8 cpe:2.3:a:wireshark:wireshark:*:*:*:*:*:*:*:*
wireshark wireshark 3.4.0 cpe:2.3:a:wireshark:wireshark:3.4.0:*:*:*:*:*:*:*
fedoraproject fedora 32 cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
oracle zfs_storage_appliance_kit 8.8 cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*

References for CVE-2020-26421

cvelogic Threat Intelligence