# CVE-2026-9759: Wireshark ROHC protocol dissector NULL pointer dereference

Source: https://junglewise.ai/threats/cve-2026-9759-wireshark-rohc-protocol-dissector-null-pointer-dereference  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-27. Updated: 2026-05-27  
License: CC BY 4.0 with a link back

CVE-2026-9759 · Severity: medium · CVSS 5.5 · Published 2026-05-27

Wireshark is a widely used network protocol analyzer for troubleshooting and security analysis. A vulnerability in its ROHC protocol component allows an attacker to crash the application by providing a specially crafted network capture file or injecting malicious traffic. This results in a denial of service, potentially disrupting network monitoring or forensic investigations.

## Quick answers

**Is CVE-2026-9759 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9759 being exploited in the wild.

**How severe is CVE-2026-9759?** Medium severity, with a CVSS score of 5.5, published 27 May 2026.

**Which products and versions are affected?** Wireshark Foundation Wireshark 4.6.0 to 4.6.5, 4.4.0 to 4.4.15.

**Is there a fix for CVE-2026-9759?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-9759 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2026-9759?** Check whether anything you run is named in the advisory. 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

A vulnerability exists in the ROHC (Robust Header Compression) dissector due to improper handling of uncompressed profiles (profile 0) when large Context Identifiers (CIDs) are present. Specifically, when a packet ends exactly at the CID field, the dissector attempts to allocate zero bytes via wmem_alloc, which returns a NULL pointer. Subsequent memory copy operations (tvb_memcpy) attempt to write to this NULL pointer or use an underflowed length value (SIZE_MAX), resulting in a crash. Exploitation requires the attacker to provide a malformed packet trace file or inject a specific multi-packet sequence into a live capture to establish the necessary ROHC context. The issue is fixed in versions 4.6.6 and 4.4.16.

## Affected products

- Wireshark Foundation Wireshark 4.6.0 to 4.6.5, 4.4.0 to 4.4.15

## Timeline

- 2026-05-19: advisory: Wireshark security advisory wnpa-sec-2026-51 published
- 2026-05-27: disclosed: CVE-2026-9759 published to NVD

## References

- [https://gitlab.com/wireshark/wireshark/-/work_items/21243](https://gitlab.com/wireshark/wireshark/-/work_items/21243)
- [https://www.wireshark.org/security/wnpa-sec-2026-51.html](https://www.wireshark.org/security/wnpa-sec-2026-51.html)