Quick answers
- Is CVE-2026-76918 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-76918 being exploited in the wild.
- How severe is CVE-2026-76918?
- Medium severity, with a CVSS score of 5.5, 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-2026-76918?
- A patch was published on 2026-08-12: Fixed in Wireshark 4.6.8 and 4.4.18 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-76918 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-76918?
- 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 buffer overflow in the SSH dissector's curve25519 key exchange handling. The root cause is in `ssh_kex_shared_secret()` which allocates a buffer sized from an attacker-controlled length value read from the wire (1–31 bytes), then passes it to `crypto_scalarmult_curve25519()` which unconditionally writes and reads exactly 32 bytes. This causes out-of-bounds heap read and write of up to 31 bytes. The vulnerability can be triggered by opening a capture file or processing a network packet with malformed curve25519 key material; no authentication or user interaction is required beyond opening the file. An attacker can crash Wireshark, causing denial of service. 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
- 2026-08-12: patched: Fixed in Wireshark 4.6.8 and 4.4.18