CVE-2026-15168: Wireshark BLF Parser Information Disclosure (CVSS 2.5)

Technical summary

CVE-2026-15168 is a CWE-457 (Use of Uninitialized Variable) flaw in Wireshark's BLF file parser. The vulnerability exists in versions 4.6.0 through 4.6.6 and 4.4.0 through 4.4.16. A crafted BLF file can trigger uninitialized variable access during parsing, potentially exposing small amounts of memory contents. The attack surface is local only; exploitation requires a user with Wireshark installed to manually open a malicious file. The vulnerability does not affect the integrity or availability of the system.

Business impact

This vulnerability poses minimal business risk for most organizations. Wireshark is primarily a traffic analysis and troubleshooting tool used by network engineers and security analysts. A real-world attack would require social engineering (convincing a user to open a suspicious BLF file), and the information disclosure is limited in scope. Organizations where Wireshark is used in security operations centers or for incident response should patch to reduce the attack surface, but this is not a critical or urgent business risk.

Affected systems

Wireshark versions 4.6.0 through 4.6.6 and 4.4.0 through 4.4.16 are affected. Consult the official Wireshark security advisory and download page to confirm patched versions available for your deployment. Organizations running Wireshark on Windows, Linux, or macOS systems should inventory instances and prioritize updates for systems handling untrusted network capture files.

Exploitability

Exploitability is low. The attack requires local file access and user interaction; an attacker must convince a Wireshark user to open a crafted BLF file. There is no remote exploitation path, no network trigger, and no privilege requirement. The CVSS vector (AV:L/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N) reflects this: attack vector is local, attack complexity is high, user interaction is required, and impact is limited to confidentiality. No public exploit code has been referenced, and this vulnerability has not been added to the CISA KEV (Known Exploited Vulnerabilities) catalog.

Remediation

Update Wireshark to a patched version released after July 8, 2026. For the 4.6 branch, upgrade to 4.6.7 or later; for the 4.4 branch, upgrade to 4.4.17 or later. Verify exact patched versions in the official Wireshark security advisory. Until patching is complete, limit user access to Wireshark on systems handling untrusted BLF files and educate users not to open BLF files from unknown sources.

Patch guidance

Check the Wireshark website and security advisories for patched releases addressing CVE-2026-15168. Wireshark provides binary packages for Windows, macOS, and Linux distributions. For enterprise deployments, coordinate updates through your standard change management process. Given the low CVSS score and local-only attack surface, this update can be prioritized after critical and high-severity patches but should be scheduled within 30–60 days.

Detection guidance

Monitor for suspicious BLF files being opened by Wireshark processes, particularly from email attachments, downloads, or external file shares. Endpoint detection and response (EDR) tools can flag unusual file access patterns following BLF parsing. Log Wireshark process execution with file arguments to detect user opening of unexpected BLF sources. Application whitelisting or sandboxing can restrict Wireshark to only trusted file locations.

Why prioritize this

This vulnerability ranks as low priority due to its narrow attack surface (local, user-interactive), limited impact (information disclosure only), and low CVSS score of 2.5. It does not affect system availability or enable code execution. Patching should be scheduled as part of routine maintenance, not as an emergency response. However, organizations where Wireshark handles sensitive network captures or is exposed to untrusted file sources should prioritize this update slightly higher.

Risk score, explained

The CVSS v3.1 score of 2.5 (LOW) accurately reflects the vulnerability's limited threat. The local attack vector (AV:L), high attack complexity (AC:H), and required user interaction (UI:R) significantly constrain exploitation. Confidentiality impact (C:L) is the only harm dimension affected, and only to a low degree. The unchanged integrity (I:N) and availability (A:N) ratings confirm no system compromise or outage risk.

Frequently asked questions