Cyber Posture

CVE-2026-5657

MediumPublic PoC

Published: 30 April 2026

Published
30 April 2026
Modified
01 May 2026
KEV Added
Patch
CVSS Score 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS Score 0.0002 5.8th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-5657 is a medium-severity Double Free (CWE-415) vulnerability in Wireshark Wireshark. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Malicious File (T1204.002); ranked at the 5.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and RA-5 (Vulnerability Monitoring and Scanning).

Threat & Defense at a Glance

What attackers do: exploitation maps to Malicious File (T1204.002) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Requires timely identification, reporting, and patching of the double free flaw in Wireshark's iLBC codec, directly preventing DoS crashes from malicious packet capture files.

detect

Vulnerability scanning detects deployments of affected Wireshark versions (4.4.0-4.4.14, 4.6.0-4.6.4) vulnerable to this iLBC double free.

prevent

Memory protection mechanisms like ASLR and heap hardening mitigate double free vulnerabilities such as the iLBC codec crash in Wireshark.

MITRE ATT&CK Enterprise TechniquesAI

T1204.002 Malicious File Execution
An adversary may rely upon a user opening a malicious file in order to gain execution.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

The vulnerability is triggered when a user opens a malicious packet capture file containing crafted iLBC data, directly mapping to T1204.002. Exploitation results in a denial-of-service crash, aligning with T1499.004 as the vulnerability enables application DoS via exploitation.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

iLBC codec crash in Wireshark 4.6.0 to 4.6.4 and 4.4.0 to 4.4.14 allows denial of service

Deeper analysisAI

CVE-2026-5657 is a vulnerability in the iLBC codec implementation within Wireshark versions 4.6.0 through 4.6.4 and 4.4.0 through 4.4.14. The flaw, classified under CWE-415 (Double Free), triggers a crash that results in a denial-of-service condition. It carries a CVSS v3.1 base score of 5.5 (AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H) and was published on 2026-04-30.

An attacker with local access can exploit this vulnerability with low complexity and no required privileges, though it demands user interaction, such as convincing a user to open a malicious packet capture file containing crafted iLBC codec data. Successful exploitation crashes the Wireshark application, causing a high-impact denial of service on availability without compromising confidentiality or integrity.

Wireshark's security advisory WNPA-SEC-2026-20 documents the issue, with related discussions and fixes tracked in GitLab issues #21113 and work item 21113. Mitigation involves updating to patched versions of Wireshark outside the affected ranges.

Details

CWE(s)

Affected Products

wireshark
wireshark
4.4.0 — 4.4.14 · 4.6.0 — 4.6.4

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References