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Wireshark disclosed a denial-of-service vulnerability in its BUSMASTER file parser that can cause the application to terminate when a user opens or reads a specially malformed packet capture file. The flaw, tracked as CVE-2026-76926 and wnpa-sec-2026-70, affects Wireshark 4.6.0 through 4.6.7 and 4.4.0 through 4.4.17, as well as TShark and software embedding libwiretap during automatic format detection.
The bug was traced to the BUSMASTER scanner's handling of an unfinished header or time statement containing a newline, which triggered Flex's fatal error path and caused the host process to call exit(2) instead of returning a normal parse error. Researchers showed that even minimal malformed input could crash the parser, and Wireshark fixed the issue by returning WTAP_ERR_BAD_FILE with a diagnostic message rather than terminating the process; the remediation is available in Wireshark 4.6.8 and 4.4.18, and the vendor said it was not aware of exploitation in the wild.
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4 events from the most recent confirmed update back to the earliest known activity.
On August 12, 2026, Wireshark published security advisory wnpa-sec-2026-70 for an abnormal exit in the BUSMASTER file parser. The advisory said malformed packet capture files could force application termination, listed affected versions 4.6.0 through 4.6.7 and 4.4.0 through 4.4.17, credited Aisle Research researchers, and said fixes were available in 4.6.8 and 4.4.18.
Wireshark issue #21435 documented a medium-severity denial-of-service flaw in the BUSMASTER file parser where malformed input could terminate the host process during automatic format detection. The report described the trigger, impact on Wireshark, TShark, and libwiretap consumers, and the remediation approach.
Gerald Combs stated that the BUSMASTER parser issue was assigned CVE-2026-76926. The CVE assignment formalized tracking of the denial-of-service vulnerability.
Wireshark fixed the malformed HEADER,TIME newline handling so the parser returns WTAP_ERR_BAD_FILE with a diagnostic instead of calling Flex's fatal exit path. The issue report states the fix was merged and the issue was closed via merge request !25907, with related merged requests !25916 and !25915.
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Wireshark disclosed a vulnerability in its Tektronix K12xx/`.rf5` file parser that can crash the packet analyzer when a user opens a specially crafted capture file. The issue, tracked as **CVE-2026-76885** and **wnpa-sec-2026-71**, stems from incorrect handling of skipped 16-byte blobs in `get_record()`, which can inflate the reported record length and lead downstream functions such as `k12_read()`, `k12_seek_read()`, and `process_packet_data()` to read past a heap buffer boundary. The bug was reported by Jaime Cavero and reproduced with AddressSanitizer in both `tshark` and `capinfos` using a synthetic malicious `.rf5` sample. Wireshark said the flaw affects versions **4.6.0 through 4.6.7** and **4.4.0 through 4.4.17**, and was fixed in **4.6.8** and **4.4.18** through merged K12 buffer-overrun patches; the project said no active exploits are known, but warned that an attacker could trigger a denial of service by convincing a target to open a malformed capture file.
Aug 21, 2026
Wireshark disclosed a denial-of-service vulnerability in its BEEP protocol dissector that can crash the packet analyzer through a stack-call overflow caused by recursive function handling. The issue is tracked as **CVE-2026-6538** and documented in advisory **`wnpa-sec-2026-23`**, with the underlying bug reported in Wireshark's issue tracker as a BEEP dissector stack-call overflow. The flaw affects Wireshark versions **4.6.0 through 4.6.4** and **4.4.0 through 4.4.14**. According to the vendor, an attacker could trigger the crash by injecting a malformed packet onto the network or by convincing a user to open a crafted capture file. Wireshark said no active exploits are known, credited Sharon Brizinov with discovery, and released fixes in versions **4.6.5** and **4.4.15**.
Aug 21, 2026
Wireshark disclosed a high-severity flaw in its Kerberos protocol dissector that can crash **Wireshark** or **TShark** when processing malformed traffic or packet captures. The bug, tracked as `CVE-2026-76924` and documented in advisory `wnpa-sec-2026-78`, stems from an out-of-bounds read while formatting a preview of a learned `EncryptionKey` from plaintext Kerberos credential data. Researchers reported that a crafted `EncKrbCredPart`, including traffic delivered over UDP/88, could trigger a heap-buffer-overflow even without a valid keytab, valid key, or successful decryption. The vendor said the issue affects Wireshark versions **4.6.0 through 4.6.7** and **4.4.0 through 4.4.17**, and it has been fixed in **4.6.8** and **4.4.18**. The root cause was that the dissector copied bounded key bytes into retained storage but still read four bytes from the original input buffer, allowing one- to three-byte keys to cause the crash; the fix reformats the preview from a zero-initialized retained buffer after the bounded copy. Wireshark said malformed packets injected onto a network or malicious packet capture files could trigger the vulnerability, and no active exploits are known.
Aug 21, 2026