Crash via nested DistinguishedName NULL dereference
Published Aug 19, 2026 · Updated Aug 20, 2026
NULL pointer dereference in Wireshark 4.6.0 through 4.6.7 and 4.4.0 through 4.4.17 allows attackers to crash the application via malformed X.509IF data. In dissect_x509if_RelativeDistinguishedName, nested DistinguishedName decoding reuses file-static DN/RDN formatter state; the inner decoder clears last_rdn_buf and the outer decoder then calls wmem_strbuf_get_str() with NULL. Reachability includes injected wire traffic and crafted packet captures, and the published evidence bounds the result to a deterministic application crash rather than code execution.
Summary
What happened
NULL pointer dereference in Wireshark 4.6.0 through 4.6.7 and 4.4.0 through 4.4.17 allows attackers to crash the application via malformed X.509IF data. In dissect_x509if_RelativeDistinguishedName, nested DistinguishedName decoding reuses file-static DN/RDN formatter state; the inner decoder clears last_rdn_buf and the outer decoder then calls wmem_strbuf_get_str() with NULL. Reachability includes injected wire traffic and crafted packet captures, and the published evidence bounds the result to a deterministic application crash rather than code execution.
The record
- CVE
- CVE-2026-76928
- Published
- Aug 19, 2026
- Updated
- Aug 20, 2026
- Vendor
- Wireshark Foundation
- Product
- Wireshark
- Classifications
- CWE-476, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 19, 2026CVE publishedPublication date reported by the CVE source.
- Aug 20, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.4.0 <4.4.18
- Affected versionversion=4.6.0 <4.6.8
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Nested DistinguishedName crash PoCproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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