CVE-2026-6533 - Improperly Controlled Sequential Memory Allocation in Wireshark

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MEDIUM

Improperly Controlled Sequential Memory Allocation in Wireshark

Published Apr 30, 2026

6.5

MEDIUM

CVSS 3.1

EPSS 0.17%

Description

Dissection engine LZ77 decompression crash in Wireshark 4.6.0 to 4.6.4 and 4.4.0 to 4.4.14 allows denial of service

Affected products

Vendor Wireshark Foundation Product Wireshark Default
unaffected
- Version
  4.4.9
  Status
  affected
  Constraints
  <4.4.15
- Version
  4.6.0
  Status
  affected
  Constraints
  <4.6.5

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor

Product

Default status

Versions

Wireshark Foundation

Wireshark

unaffected

Version	Status	Constraints
4.4.9	affected	<4.4.15
4.6.0	affected	<4.6.5

Red Hat Enterprise Linux 10

wireshark

Fix deferred
Red Hat Enterprise Linux 6

wireshark

Fix deferred
Red Hat Enterprise Linux 7

wireshark

Fix deferred
Red Hat Enterprise Linux 8

wireshark

Fix deferred
Red Hat Enterprise Linux 9

wireshark

Fix deferred

Product	Package	State	Advisory
Red Hat Enterprise Linux 10	wireshark	Fix deferred	n/a
Red Hat Enterprise Linux 6	wireshark	Fix deferred	n/a
Red Hat Enterprise Linux 7	wireshark	Fix deferred	n/a
Red Hat Enterprise Linux 8	wireshark	Fix deferred	n/a
Red Hat Enterprise Linux 9	wireshark	Fix deferred	n/a

Remediation

Vendor solution

Upgrade to version 4.6.5 or above

Red Hat mitigation

To mitigate this issue, users should avoid opening untrusted or suspicious packet capture files with Wireshark. Running Wireshark in a sandboxed environment can further limit the potential impact of processing malicious data.

Weaknesses (2)

CWE-1325

CWE-409

References (7)

https://access.redhat.com/security/cve/CVE-2026-6533
Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2464042
Issue Tracking
https://gitlab.com/wireshark/wireshark/-/issues/21127
issue-trackingpermissions-requiredExploitIssue TrackingThird Party Advisory
https://gitlab.com/wireshark/wireshark/-/work_items/21127
exploitIssue TrackingThird Party Advisory
https://nvd.nist.gov/vuln/detail/CVE-2026-6533
https://www.cve.org/CVERecord?id=CVE-2026-6533
https://www.wireshark.org/security/wnpa-sec-2026-28.html
Vendor Advisory

Link	Providers	Tags
https://access.redhat.com/security/cve/CVE-2026-6533		Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2464042		Issue Tracking
https://gitlab.com/wireshark/wireshark/-/issues/21127		issue-trackingpermissions-requiredExploitIssue TrackingThird Party Advisory
https://gitlab.com/wireshark/wireshark/-/work_items/21127		exploitIssue TrackingThird Party Advisory
https://nvd.nist.gov/vuln/detail/CVE-2026-6533
https://www.cve.org/CVERecord?id=CVE-2026-6533
https://www.wireshark.org/security/wnpa-sec-2026-28.html		Vendor Advisory