CVE-2026-68119
tcp: initialize standalone TCP-AO response padding
Description
In the Linux kernel, the following vulnerability has been resolved: tcp: initialize standalone TCP-AO response padding tcp_v4_send_ack() and tcp_v6_send_response() construct standalone TCP responses with TCP-AO options. The option length carries the actual MAC length, but the TCP header length includes the option rounded up to a four-byte boundary. tcp_ao_hash_hdr() writes the MAC only. Thus, when the MAC length is not four-byte aligned, the one to three bytes after the MAC are left uninitialized and may be transmitted. For the normal TCP-AO hashing mode, those bytes also have to be initialized before computing the MAC. Initialize only the alignment padding in the TCP-AO branches, before hashing the header. Use TCPOPT_NOP, as in the normal TCP-AO output path. This avoids adding work to non-AO TCP responses while preserving a valid authenticated header.
INFO
Published Date :
Aug. 10, 2026, 1:19 p.m.
Last Modified :
Aug. 17, 2026, 5:18 a.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Initialize TCP-AO alignment padding with TCPOPT_NOP.
- Ensure padding is initialized before MAC computation.
- Apply the fix in tcp_v4_send_ack and tcp_v6_send_response.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-68119.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-68119 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-68119
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-68119 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-68119 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'bbb7db8c74b0b5d17a695136f0f0806ecd0118f6', 'versionType': 'git'}, {'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'fadaff3f66e124c3a62237f9c881819a8ac90309', 'versionType': 'git'}, {'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'a859b280441fb02f64ed4037f03d5c0c34a7a595', 'versionType': 'git'}, {'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'e1a9d3cc11829c5414a75eb39c704f461936eb24', 'versionType': 'git'}], 'programFiles': ['net/ipv4/tcp_ipv4.c', 'net/ipv6/tcp_ipv6.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.101', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.42', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.6', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc5', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ipv4/tcp_ipv4.c', 'net/ipv6/tcp_ipv6.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'bbb7db8c74b0b5d17a695136f0f0806ecd0118f6', 'versionType': 'git'}, {'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'fadaff3f66e124c3a62237f9c881819a8ac90309', 'versionType': 'git'}, {'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'a859b280441fb02f64ed4037f03d5c0c34a7a595', 'versionType': 'git'}, {'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'e1a9d3cc11829c5414a75eb39c704f461936eb24', 'versionType': 'git'}], 'programFiles': ['net/ipv4/tcp_ipv4.c', 'net/ipv6/tcp_ipv6.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.101', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.42', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.6', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ipv4/tcp_ipv4.c', 'net/ipv6/tcp_ipv6.c'], 'defaultStatus': 'affected'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 10, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'bbb7db8c74b0b5d17a695136f0f0806ecd0118f6', 'versionType': 'git'}, {'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'fadaff3f66e124c3a62237f9c881819a8ac90309', 'versionType': 'git'}, {'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'a859b280441fb02f64ed4037f03d5c0c34a7a595', 'versionType': 'git'}, {'status': 'affected', 'version': 'decde2586b34b99684faff1eab41e5c496c27fb6', 'lessThan': 'e1a9d3cc11829c5414a75eb39c704f461936eb24', 'versionType': 'git'}], 'programFiles': ['net/ipv4/tcp_ipv4.c', 'net/ipv6/tcp_ipv6.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.101', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.42', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.6', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc5', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ipv4/tcp_ipv4.c', 'net/ipv6/tcp_ipv6.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: tcp: initialize standalone TCP-AO response padding tcp_v4_send_ack() and tcp_v6_send_response() construct standalone TCP responses with TCP-AO options. The option length carries the actual MAC length, but the TCP header length includes the option rounded up to a four-byte boundary. tcp_ao_hash_hdr() writes the MAC only. Thus, when the MAC length is not four-byte aligned, the one to three bytes after the MAC are left uninitialized and may be transmitted. For the normal TCP-AO hashing mode, those bytes also have to be initialized before computing the MAC. Initialize only the alignment padding in the TCP-AO branches, before hashing the header. Use TCPOPT_NOP, as in the normal TCP-AO output path. This avoids adding work to non-AO TCP responses while preserving a valid authenticated header. Added Reference https://git.kernel.org/stable/c/a859b280441fb02f64ed4037f03d5c0c34a7a595 Added Reference https://git.kernel.org/stable/c/bbb7db8c74b0b5d17a695136f0f0806ecd0118f6 Added Reference https://git.kernel.org/stable/c/e1a9d3cc11829c5414a75eb39c704f461936eb24 Added Reference https://git.kernel.org/stable/c/fadaff3f66e124c3a62237f9c881819a8ac90309