CVE-2025-11626 Overview
CVE-2025-11626 is an infinite loop vulnerability in the MongoDB (MONGO) protocol dissector shipped with Wireshark. The flaw affects Wireshark versions 4.4.0 through 4.4.9 and 4.2.0 through 4.2.13. A malformed MONGO packet processed by the dissector causes the affected component to enter an infinite loop, exhausting CPU resources and preventing further packet analysis. The condition maps to CWE-835: Loop with Unreachable Exit Condition. Exploitation requires local user interaction, such as opening a crafted capture file or injecting malicious traffic into a live capture session.
Critical Impact
A crafted MONGO packet or capture file forces Wireshark into an infinite loop, causing denial of service on the analyst workstation and disrupting network traffic analysis workflows.
Affected Products
- Wireshark 4.4.0 through 4.4.9
- Wireshark 4.2.0 through 4.2.13
- The MONGO protocol dissector component (wireshark:wireshark)
Discovery Timeline
- 2025-10-10 - CVE-2025-11626 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-11626
Vulnerability Analysis
The vulnerability resides in the MONGO dissector, which parses MongoDB wire protocol messages inside Wireshark. When the dissector encounters a specifically malformed MONGO message, a parsing loop fails to advance its offset or reach its termination condition. The dissector then repeatedly processes the same input, consuming CPU cycles indefinitely.
Because the loop runs on the main dissection thread, the Wireshark process becomes unresponsive. Analysts lose the ability to inspect the active capture, and long-running captures may need to be terminated. The impact is confined to availability. The advisory records no memory corruption, no information disclosure, and no integrity impact.
Exploitation requires local interaction. An attacker delivers a crafted .pcap or .pcapng file to a target analyst, or injects malformed MONGO traffic onto a network segment where Wireshark or tshark is capturing live.
Root Cause
The root cause is an unreachable exit condition in the MONGO dissector's message parsing routine. Length or offset validation on attacker-controlled fields is insufficient, allowing an iteration variable to remain unchanged across loop passes. See the Wireshark Security Advisory WNPA-SEC-2025-04 and GitLab Issue #20724 for upstream analysis.
Attack Vector
The attack vector is local and requires user interaction. Two realistic paths exist:
- An analyst opens a malicious capture file received via email, chat, shared drive, or incident-response artifact exchange.
- Wireshark or tshark performs live capture on a segment where an attacker can inject crafted MONGO packets on TCP port 27017 or any port configured for MONGO dissection.
No authentication is required at the network layer, but the vulnerable process is the analyst's Wireshark instance rather than a network-exposed service.
No verified proof-of-concept code is publicly available. Refer to
the Wireshark advisory and GitLab issue for reproduction details.
Detection Methods for CVE-2025-11626
Indicators of Compromise
- Wireshark or tshark processes consuming sustained 100% CPU on a single core while dissecting MONGO traffic or a specific capture file.
- Capture files that trigger unresponsiveness immediately after loading, particularly those containing MongoDB (TCP 27017) traffic from untrusted sources.
- Anomalous MONGO messages with malformed length fields observed in stored .pcap or .pcapng files.
Detection Strategies
- Inventory endpoints running vulnerable Wireshark versions (4.4.0–4.4.9, 4.2.0–4.2.13) using software asset management or endpoint telemetry.
- Flag capture files received from external sources and require analysis in isolated, non-production environments.
- Correlate Wireshark process hangs with recent file-open events or live capture sessions on segments carrying MongoDB traffic.
Monitoring Recommendations
- Monitor for high CPU utilization tied to wireshark.exe, Wireshark, or tshark processes on analyst workstations.
- Alert on execution of vulnerable Wireshark binaries in incident response and SOC environments until patched.
- Track distribution of externally sourced capture files through email gateways and file-sharing platforms.
How to Mitigate CVE-2025-11626
Immediate Actions Required
- Upgrade Wireshark to a fixed release above 4.4.9 in the 4.4.x branch or above 4.2.13 in the 4.2.x branch, per WNPA-SEC-2025-04.
- Restrict opening of capture files sourced from untrusted parties on analyst workstations.
- Prefer tshark in constrained environments and terminate any process observed hanging on MONGO dissection.
Patch Information
The Wireshark Foundation addressed the infinite loop in the MONGO dissector in point releases following 4.4.9 and 4.2.13. Details are published in Wireshark Security Advisory WNPA-SEC-2025-04 and tracked upstream in GitLab Issue #20724. Apply the vendor-provided update from the official Wireshark download channels or through your operating system's package manager.
Workarounds
- Disable the MONGO dissector in Wireshark via Analyze → Enabled Protocols and unchecking MONGO until patching is complete.
- Avoid live captures on network segments carrying untrusted MongoDB traffic on TCP port 27017.
- Analyze suspicious capture files inside disposable virtual machines that can be reset if Wireshark becomes unresponsive.
# Disable the MONGO dissector from the command line by editing the
# disabled_protos preference file in the Wireshark profile directory.
# Example path on Linux:
# ~/.config/wireshark/disabled_protos
# Add the following line to disable MONGO dissection:
mongo
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
