CVE-2026-76919
Description
A flaw was found in Wireshark. A remote attacker could exploit a denial of service vulnerability in the ESS protocol dissector by processing a specially crafted network packet. This could lead to the application crashing, preventing network traffic analysis. The impact is limited to the availability of the Wireshark application itself.
Statement
This Moderate impact denial of service vulnerability affects Wireshark's ESS protocol dissector. An attacker can crash the application by providing a specially crafted network packet for analysis. The impact is limited to the availability of the Wireshark application, requiring user interaction to process the malicious input.
Mitigation
To mitigate this issue prior to patching, disable the ESS protocol dissector by running tshark --disable-protocol ess or unchecking ESS under Analyze > Enabled Protocols. Additionally, avoid opening packet capture files from untrusted sources and restrict live capture to trusted networks using host firewalls. On systems where packet analysis is non-essential, remove the wireshark package entirely or restrict execution permissions strictly to authorized administrators.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | 7.5 | 5.3 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | Required | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Red Hat CVSS v3 Score Explanation
For Red Hat products, exploitation normally requires an operator to process untrusted network data (open a capture or run live dissection on traffic containing malformed ESS), so UI:R is the right score
Understanding the Weakness (CWE)
Availability,Integrity,Other
Technical Impact: Other
Initial variables usually contain junk, which can not be trusted for consistency. This can lead to denial of service conditions, or modify control flow in unexpected ways. In some cases, an attacker can "pre-initialize" the variable using previous actions, which might enable code execution. This can cause a race condition if a lock variable check passes when it should not.
Authorization,Other
Technical Impact: Other
Strings that are not initialized are especially dangerous, since many functions expect a null at the end -- and only at the end -- of a string.
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