Quick answers
- Is CVE-2026-76887 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-76887 being exploited in the wild.
- How severe is CVE-2026-76887?
- Low severity, with a CVSS score of 3.1, 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-2026-76887?
- A patch was published on 2026-08-19: Wireshark 4.6.8 and 4.4.18 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-76887 attacked?
- It is attacked over the network or with local access.
- Am I affected by CVE-2026-76887?
- 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 exists in epan/reassemble.c where the generic block-sequence reassembly engine accumulates fragment lengths in a 32-bit unsigned integer without overflow checking. When the sum of fragment lengths exceeds UINT32_MAX, the accumulated value wraps to a smaller value, resulting in an undersized g_malloc() allocation. Subsequent code then copies all fragments at their full length into this undersized buffer, causing a heap buffer overflow. The attack requires processing >4 GiB of reassembled fragment data in a single sequence via SMTP, DICOM, or WebSocket protocols; this can occur through capture file dissection or live network monitoring. The crash is guaranteed (denial of service), though code execution is not demonstrated. Patches are available in Wireshark 4.6.8 and 4.4.18.
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: Wireshark 4.6.8 and 4.4.18 released