Is CVE-2026-76929 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-76929 being exploited in the wild.

How severe is CVE-2026-76929?

Medium severity, with a CVSS score of 4.7, published 19 August 2026.

Which products and versions are affected?

Wireshark 4.6.0 to 4.6.7, 4.4.0 to 4.4.17.

Is there a fix for CVE-2026-76929?

A patch was published on 2026-08-19: Fixed in Wireshark 4.6.8, 4.4.18 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-76929 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-76929?

Check whether you run Wireshark at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-76929: Wireshark pcapng file parser heap out-of-bounds read

CVE-2026-76929 · Severity: medium · CVSS 4.7 · Published 2026-08-19

Wireshark is a network traffic analysis tool used to inspect and troubleshoot network communications. A flaw in its pcapng file parser can be triggered by opening a malformed packet capture file, causing the application to crash and denying service to analysts who depend on it for network diagnostics. An attacker could distribute a crafted capture file to cause denial of service.

Technologies: Wireshark. Vendors: Wireshark.

Quick answers

Is CVE-2026-76929 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-76929 being exploited in the wild.
How severe is CVE-2026-76929?: Medium severity, with a CVSS score of 4.7, published 19 August 2026.
Which products and versions are affected?: Wireshark 4.6.0 to 4.6.7, 4.4.0 to 4.4.17.
Is there a fix for CVE-2026-76929?: A patch was published on 2026-08-19: Fixed in Wireshark 4.6.8, 4.4.18 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-76929 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-76929?: Check whether you run Wireshark at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a heap-based out-of-bounds read in the Netflix pcapng TCPINFO custom option parser (wiretap/pcapng-netflix-custom.c). The parser validates only a 4-byte subtype field but then unconditionally performs two 8-byte timestamp reads without checking payload length. A malformed pcapng custom block with an empty TCPINFO payload triggers an 8-byte out-of-bounds read, causing a crash via AddressSanitizer detection or direct heap corruption. No authentication or user interaction is required beyond opening the malicious file; the crash occurs during initial packet capture parsing before any dissection. Patches are available in Wireshark 4.6.8 and 4.4.18+, which add length validation before the timestamp reads.

Affected products

Wireshark Wireshark 4.6.0 to 4.6.7, 4.4.0 to 4.4.17

Timeline

2026-08-12: disclosed
2026-08-19: patched: Fixed in Wireshark 4.6.8, 4.4.18

References

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