CVE-2021-39926

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of...

7.5 HighFix available

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of service via packet injection or crafted capture file

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

7.96%Up 6.9 points since Nov 20, 2021

What each source reports

CVE List Score used 7.5

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of service via packet injection or crafted capture file

Record: CVE-2021-39926
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

EUVDEUVD-2021-26282 7.5

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of service via packet injection or crafted capture file

Record: EUVD-2021-26282
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-03

GitHub AdvisoriesGHSA-g42c-hpcx-483f 7.5

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of...

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of service via packet injection or crafted capture file

Record: GHSA-g42c-hpcx-483f
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-120
Updated: 2026-11-02

NVD 7.5

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of service via packet injection or crafted capture file

Record: CVE-2021-39926
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-120
Updated: 2026-11-02

OSVALPINE-CVE-2021-39926 7.5

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of service via packet injection or crafted capture file

Record: ALPINE-CVE-2021-39926
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-03

OSVAZL-7414 7.5

CVE-2021-39926 affecting package wireshark for versions less than 3.4.14-1

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of service via packet injection or crafted capture file

Record: AZL-7414
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

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OSV 7.5

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of service via packet injection or crafted capture file

Record: CVE-2021-39926
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2021-39926 7.5

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of service via packet injection or crafted capture file

Record: DEBIAN-CVE-2021-39926
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-39926 7.5

Buffer overflow in the Bluetooth HCI_ISO dissector in Wireshark 3.4.0 to 3.4.9 allows denial of service via packet injection or crafted capture file

Record: UBUNTU-CVE-2021-39926
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVMGASA-2021-0518 No score

Updated wireshark packages fix security vulnerability

IPPUSB dissector crash (CVE-2021-39920). Modbus dissector crash (CVE-2021-39921). C12.22 dissector crash (CVE-2021-39922). PNRP dissector large loop (wnpa-sec-2021-11). Bluetooth DHT dissector large loop (CVE-2021-39924). Bluetooth SDP dissector crash (CVE-2021-39925). Bluetooth HCI_ISO dissector crash (CVE-2021-39926). IEEE 802.11 dissector crash (CVE-2021-39928). Bluetooth DHT dissector crash (CVE-2021-39929).

Record: MGASA-2021-0518
Updated: 2026-11-02

OSVopenSUSE-SU-2021:1566-1 No score

Security update for wireshark

This update for wireshark fixes the following issues:

Update to Wireshark 3.4.10:
CVE-2021-39920: IPPUSB dissector crash (bsc#1192830).
CVE-2021-39921: Modbus dissector crash (bsc#1192830).
CVE-2021-39922: C12.22 dissector crash (bsc#1192830).
CVE-2021-39924: Bluetooth DHT dissector large loop (bsc#1192830).
CVE-2021-39925: Bluetooth SDP dissector crash (bsc#1192830).
CVE-2021-39926: Bluetooth HCI_ISO dissector crash (bsc#1192830).
CVE-2021-39928: IEEE 802.11 dissector crash (bsc#1192830).
CVE-2021-39929: Bluetooth DHT dissector crash (bsc#1192830).

This update was imported from the SUSE:SLE-15:Update update project.

Record: openSUSE-SU-2021:1566-1
Updated: 2026-11-02

OSVopenSUSE-SU-2021:3938-1 No score

Security update for wireshark

This update for wireshark fixes the following issues:

Update to Wireshark 3.4.10:
CVE-2021-39920: IPPUSB dissector crash (bsc#1192830).
CVE-2021-39921: Modbus dissector crash (bsc#1192830).
CVE-2021-39922: C12.22 dissector crash (bsc#1192830).
CVE-2021-39924: Bluetooth DHT dissector large loop (bsc#1192830).
CVE-2021-39925: Bluetooth SDP dissector crash (bsc#1192830).
CVE-2021-39926: Bluetooth HCI_ISO dissector crash (bsc#1192830).
CVE-2021-39928: IEEE 802.11 dissector crash (bsc#1192830).
CVE-2021-39929: Bluetooth DHT dissector crash (bsc#1192830).

Record: openSUSE-SU-2021:3938-1
Updated: 2026-11-02

OSVopenSUSE-SU-2024:11641-1 No score

libwireshark14-3.4.10-1.1 on GA media

These are all security issues fixed in the libwireshark14-3.4.10-1.1 package on the GA media of openSUSE Tumbleweed.

Record: openSUSE-SU-2024:11641-1
Updated: 2026-11-02

OSVSUSE-SU-2021:3938-1 No score

Security update for wireshark

This update for wireshark fixes the following issues:

Update to Wireshark 3.4.10:
CVE-2021-39920: IPPUSB dissector crash (bsc#1192830).
CVE-2021-39921: Modbus dissector crash (bsc#1192830).
CVE-2021-39922: C12.22 dissector crash (bsc#1192830).
CVE-2021-39924: Bluetooth DHT dissector large loop (bsc#1192830).
CVE-2021-39925: Bluetooth SDP dissector crash (bsc#1192830).
CVE-2021-39926: Bluetooth HCI_ISO dissector crash (bsc#1192830).
CVE-2021-39928: IEEE 802.11 dissector crash (bsc#1192830).
CVE-2021-39929: Bluetooth DHT dissector crash (bsc#1192830).

Record: SUSE-SU-2021:3938-1
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`wireshark` Alpine:v3.15	3.4.0 up to 3.4.13-r0	3.4.13-r0
`wireshark` Alpine:v3.16	3.4.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.17	3.4.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.18	3.4.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.19	3.4.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.20	3.4.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.21	3.4.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.22	3.4.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.23	3.4.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.24	3.4.0 up to 3.4.11-r0	3.4.11-r0

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Affected packages
Package	Affected	Fixed
`wireshark` Azure Linux:2	before 3.4.14-1	3.4.14-1
`wireshark` Debian:12	before 3.6.0-1	3.6.0-1
`wireshark` Debian:13	before 3.6.0-1	3.6.0-1
`wireshark` Debian:14	before 3.6.0-1	3.6.0-1
`wireshark` Debian:11 From an advisory covering 12 CVEs	before 3.4.10-0+deb11u1, plus listed versions 3.4.4-13.4.6-1~exp13.4.7-13.4.7-1~exp13.4.8-13.4.9-1	3.4.10-0+deb11u1
`wireshark` Mageia:8 From an advisory covering 8 CVEs	before 3.4.10-1.mga8	3.4.10-1.mga8
`wireshark` SUSE:Linux Enterprise Module for Basesystem 15 SP2 From an advisory covering 8 CVEs	before 3.4.10-3.62.1	3.4.10-3.62.1
`wireshark` SUSE:Linux Enterprise Module for Basesystem 15 SP3 From an advisory covering 8 CVEs	before 3.4.10-3.62.1	3.4.10-3.62.1
`wireshark` SUSE:Linux Enterprise Module for Desktop Applications 15 SP2 From an advisory covering 8 CVEs	before 3.4.10-3.62.1	3.4.10-3.62.1
`wireshark` SUSE:Linux Enterprise Module for Desktop Applications 15 SP3 From an advisory covering 8 CVEs	before 3.4.10-3.62.1	3.4.10-3.62.1
`wireshark` Ubuntu:Pro:14.04:LTS	All versions, plus listed versions 1.10.2-11.10.3-11.10.5-1ubuntu11.10.5-21.10.6-1 Show 9 moreShow less 1.12.1+g01b65bf-4+deb8u11ubuntu0.14.04.12.6.3-1~ubuntu14.04.12.6.4-2~ubuntu14.04.12.6.5-1~ubuntu14.04.12.6.6-1~ubuntu14.04.02.6.8-1~ubuntu14.04.0~esm12.6.10-1~ubuntu14.04.0~esm12.6.10-1~ubuntu14.04.0~esm22.6.10-1~ubuntu14.04.0~esm3	None known
`wireshark` Ubuntu:Pro:16.04:LTS	All versions, plus listed versions 1.12.7+g7fc8978-11.12.8+g5b6e543-22.0.1+g59ea380-3build12.0.2+ga16e22e-12.2.6+g32dac6a-2ubuntu0.16.04 Show 8 moreShow less 2.6.3-1~ubuntu16.04.12.6.4-2~ubuntu16.04.02.6.5-1~ubuntu16.04.02.6.6-1~ubuntu16.04.02.6.8-1~ubuntu16.04.02.6.10-1~ubuntu16.04.02.6.10-1~ubuntu16.04.0+esm12.6.10-1~ubuntu16.04.0+esm2	None known
`wireshark` Ubuntu:Pro:18.04:LTS	All versions, plus listed versions 2.4.2-12.4.3-12.4.4-12.4.5-12.6.3-1~ubuntu18.04.1 Show 7 moreShow less 2.6.4-2~ubuntu18.04.02.6.5-1~ubuntu18.04.02.6.6-1~ubuntu18.04.02.6.8-1~ubuntu18.04.02.6.10-1~ubuntu18.04.02.6.10-1~ubuntu18.04.0+esm12.6.10-1~ubuntu18.04.0+esm2	None known
`wireshark` Ubuntu:Pro:20.04:LTS	All versions, plus listed versions 3.0.5-13.0.7-13.2.1-13.2.2-13.2.3-13.2.3-1ubuntu0.1~esm13.2.3-1ubuntu0.1~esm2	None known
`wireshark` Ubuntu:Pro:22.04:LTS	All versions, plus listed versions 3.4.7-1~exp13.4.9-13.6.2-1ubuntu13.6.2-23.6.2-2ubuntu0.1~esm1	None known
`wireshark` openSUSE:Leap 15.2 From an advisory covering 8 CVEs	before 3.4.10-lp152.2.21.1	3.4.10-lp152.2.21.1
`wireshark` openSUSE:Leap 15.3 From an advisory covering 8 CVEs	before 3.4.10-3.62.1	3.4.10-3.62.1
`wireshark` openSUSE:Tumbleweed From an advisory covering 8 CVEs	before 3.4.10-1.1	3.4.10-1.1

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	affected, aliases, references	OSV
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-39926 is a high vulnerability (CVSS 7.5) in Wireshark, published November 19, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 7.96%, the 94th percentile. Fixed in wireshark 3.4.13-r0.

References

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