CVE-2026-96423
published 2026-09-29CVE-2026-96423: X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service
PriorityP425high7.1CVSS 3.1
AVLACLPRNUIRSUCHINAH
EPSS
0.13%
2.6th percentile
X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service
Affected
6 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| gitlab | wireshark | — | — |
| wireshark | wireshark | — | — |
| wireshark | wireshark | >= 4.4.0 < 4.4.19 | 4.4.19 |
| wireshark | wireshark | >= 4.6.0 < 4.6.9 | 4.6.9 |
| wireshark_foundation | wireshark | >= 4.4.0 < 4.4.19 | 4.4.19 |
| wireshark_foundation | wireshark | >= 4.6.0 < 4.6.9 | 4.6.9 |
CVSS provenance
nvdv3.17.1HIGHCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
vendor_redhat5.5MEDIUM
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Red Hat
wireshark: Heap-based Buffer Overflow in Wireshark
vendor_redhat·2026-09-29·CVSS 5.5
CVE-2026-96423 [MEDIUM] CWE-787 wireshark: Heap-based Buffer Overflow in Wireshark
wireshark: Heap-based Buffer Overflow in Wireshark
A flaw was found in Wireshark. A heap-based buffer overflow in the X11 protocol dissector allows an attacker to cause a Denial of Service (DoS) by injecting malformed packets or providing a crafted capture file. Successful exploitation leads to an application crash, disrupting network packet inspection.
Mitigation: Disable the X11 protocol dissector if analyzing network traffic that does not require X11 packet decoding.
For command-line analysis using tshark, disable the protocol at runtime:
```
tshark --disable-protocol x11 -r
```
For persistent user configuration, add the protocol identifier to the disabled protocols file:
```
mkdir -p ~/.config/wireshark
echo "x11" >> ~/.config/wireshark/disabled_protos
```
In the Wireshark graphical
GitLab
Heap-based Buffer Overflow in Wireshark
vendor_gitlab·2026-09-29·CVSS 5.5
CVE-2026-96423 [MEDIUM] CWE-122 Heap-based Buffer Overflow in Wireshark
Heap-based Buffer Overflow in Wireshark
X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service
Affected products: Wireshark
Affected versions: >=4.6.0, =4.4.0, <4.4.19 (affected)
Solution: Upgrade to version 4.6.9 or above
Credit: Claude and Ada Logics
VulDB
Wireshark up to 4.4.18/4.6.8 Dissector denial of service (Nessus ID 362908)
vuldb·2026-10-05·CVSS 5.5
CVE-2026-96423 [MEDIUM] Wireshark up to 4.4.18/4.6.8 Dissector denial of service (Nessus ID 362908)
A vulnerability has been found in Wireshark up to 4.4.18/4.6.8 and classified as problematic. This affects an unknown part of the component Dissector. The manipulation leads to denial of service.
This vulnerability is documented as CVE-2026-96423. The attack needs to be performed locally. There is not any exploit available.
The affected component should be upgraded.
GHSA
X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service
ghsa_unreviewed·2026-09-29
CVE-2026-96423 [MEDIUM] CWE-122 X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service
X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-96423 wireshark: Heap-based Buffer Overflow in Wireshark [fedora-all]
bugzilla·2026-09-29·CVSS 5.5
CVE-2026-96423 [MEDIUM] CVE-2026-96423 wireshark: Heap-based Buffer Overflow in Wireshark [fedora-all]
CVE-2026-96423 wireshark: Heap-based Buffer Overflow in Wireshark [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service
Bugzilla
CVE-2026-96423 wireshark: Heap-based Buffer Overflow in Wireshark
bugzilla·2026-09-29·CVSS 5.5
CVE-2026-96423 [MEDIUM] CVE-2026-96423 wireshark: Heap-based Buffer Overflow in Wireshark
CVE-2026-96423 wireshark: Heap-based Buffer Overflow in Wireshark
X11 protocol dissector crash in 4.6.0 to 4.6.8 and 4.4.0 to 4.4.18 allows denial of service
2026-09-29
Published