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Wireshark disclosed and patched a high-severity vulnerability in its C12.22 protocol dissector that can crash the application when processing malformed traffic or packet captures. The flaw, tracked as CVE-2026-76886 and covered by advisory wnpa-sec-2026-75, stems from the EAX/CMAC decryption path, where Eax_Decrypt() accepts 32-bit lengths but passes them into 16-bit CMAC helper logic, causing integer truncation, undersized heap allocation, and subsequent oversized memcpy() operations that lead to a heap-buffer overflow.
The vulnerable code path is reachable through reassembled C12.22 traffic over TCP/1153 when c1222.decrypt is enabled and a matching decryption-table entry exists; researchers reported that a crafted 65,576-byte MESSAGE can reliably trigger the crash. Wireshark said affected versions are 4.6.0 through 4.6.7 and 4.4.0 through 4.4.17, with fixes released in 4.6.8 and 4.4.18 that reject oversized CMAC inputs before allocation. The issue was reported by researchers from Aisle Research, O2Lab, and TAMU, and Wireshark said no active exploits are known.
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Wireshark published security advisory wnpa-sec-2026-75 for a C12.22 protocol dissector crash affecting versions 4.6.0 through 4.6.7 and 4.4.0 through 4.4.17. The advisory states the issue is fixed in versions 4.6.8 and 4.4.18 and that no exploits are known.
On its issue tracker, Wireshark disclosed and documented the heap-buffer-overflow vulnerability in EAX/CMAC handling for large C12.22 cleartext-authentication payloads. The report included technical root-cause details, proof-of-concept artifacts, and confirmation that the patch prevented the ASan-detected crash.
Wireshark merged fixes that reject oversized CMAC inputs before allocation, preventing the heap overflow in EAX/CMAC processing. The issue was then closed with references to merge requests !25925, !25937, !25938, and commit 360bdc60.
Aisle Research reported a high-severity heap-buffer-overflow vulnerability in Wireshark's EAX/CMAC handling for large C12.22 cleartext-authentication payloads, later assigned CVE-2026-76886. The issue can be triggered via reassembled C12.22 traffic when decryption is enabled and a matching key entry exists.
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Wireshark disclosed **CVE-2026-5653**, a heap-based buffer overflow in its DCP-ETSI protocol dissector that can crash the network protocol analyzer and cause a denial of service. The flaw affects Wireshark versions `4.6.0` through `4.6.4` and `4.4.0` through `4.4.14`, and was assigned **CWE-122** with a **CVSS v3.1 score of 5.5**. According to the advisory, an attacker could trigger the issue by injecting a malformed packet onto the network or by convincing a user to open a crafted packet capture file. Wireshark fixed the vulnerability in versions `4.6.5` and `4.4.15`; the issue was discovered by Alexandre de Oliveira, and the vendor said no active exploits were known at the time of disclosure.
Aug 21, 2026
Wireshark disclosed and fixed **CVE-2026-15166**, a stack-based buffer overflow in 802.11 EAPOL-Key decryption handling within `Dot11DecryptDecryptKeyData()`. The flaw stems from attacker-controlled EAPOL length fields reaching a `memcpy` into a fixed 1024-byte stack buffer without proper bounds checking on the decrypt path, allowing a malformed frame to corrupt the stack. The issue was reported in Wireshark's `tshark` processing and was reproduced with AddressSanitizer against commit `b260b00b861aef491d11043d2a8c9dd2615cdb9e` using the shipped `wpa-Induction.pcap` test capture. Wireshark said the vulnerability affects versions **4.6.0 through 4.6.6** and **4.4.0 through 4.4.16**, and could let an attacker crash the application by convincing a user to open a malformed packet trace file. The original report said that, when WPA decryption is enabled and a valid Security Association exists for the BSSID, a single crafted EAPOL-Key frame can overflow the buffer by roughly 1000 bytes, creating potential **RCE-class** impact in addition to denial of service. Wireshark released fixes in **4.6.7** and **4.4.17** and said it was not aware of active exploitation.
Aug 21, 2026
Wireshark disclosed and patched multiple vulnerabilities in its Catapult DCT2000 handling code, including a protocol dissector crash tracked as **CVE-2026-15174** and a separate file parser flaw later assigned **CVE-2026-76883**. The first issue, published as advisory **`wnpa-sec-2026-52`**, affects Wireshark versions **4.6.0 through 4.6.6** and **4.4.0 through 4.4.16** and can be triggered by a malformed packet on the wire or by opening a malformed packet trace file, causing the application to crash. A later advisory, **`wnpa-sec-2026-74`**, covers a Catapult DCT2000 file parser crash affecting versions **4.6.0 through 4.6.7** and **4.4.0 through 4.4.17**, fixed in **4.6.8** and **4.4.18**. Separately, a GitLab issue detailed an off-by-one heap out-of-bounds write in `parse_line()` within `wiretap/catapult_dct2000.c`, where the parser allocates `floor(data_chars/2)` bytes but may write `ceil(data_chars/2)` bytes when the input length is odd; developers confirmed the bug, noted practical triggering requires exactly **2049 bytes**, and merged fixes. Wireshark said no exploits are known for the disclosed issues and advised users to upgrade to patched releases.
Aug 21, 2026