CVE-2026-76927
Description
A flaw was found in Wireshark. A remote attacker could exploit a vulnerability in the H.245 protocol dissector. By crafting and sending malformed H.245 protocol data, an attacker could cause the Wireshark application to crash when a user processes this untrusted network data, leading to a denial of service.
Statement
This localized Denial of Service vulnerability is rated Moderate because it solely causes application instability, leaving the underlying system and data secure. Furthermore, the exploit cannot trigger autonomously; it strictly requires a user to actively process crafted live network traffic or open a malicious capture file.
Mitigation
To mitigate this issue, disable the H.245 protocol dissector by running tshark --disable-protocol h245 or unchecking H.245 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 | 4.7 |
| Attack Vector | Network | Network | Local |
| Attack Complexity | Low | Low | High |
| Privileges Required | None | None | None |
| User Interaction | Required | None | Required |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
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:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H
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
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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