CVE-2026-63834
batman-adv: tp_meter: restrict number of unacked list entries
Description
In the Linux kernel, the following vulnerability has been resolved: batman-adv: tp_meter: restrict number of unacked list entries When the unacked_list is unbound, an attacker could send messages with small lengths and appropriated seqno + gaps to force the receiver to allocate more and more unacked_list entries. And the end either causing an out-of-memory situation or increase the management overhead for the (large) list that significant portions of CPU cycles are wasted in searching through the list. When limiting the list to a specific number, it is important to still correctly add a new entry to the list. But if the list became larger than the limit, the last entry of the list (with the highest seqno) must be dropped to still allow the earlier seqnos to finish and therefore to continue the process. Otherwise, the process might get stuck with too high seqnos which are not handled by batadv_tp_ack_unordered().
INFO
Published Date :
July 19, 2026, 12:16 p.m.
Last Modified :
July 19, 2026, 12:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-63834
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply kernel patch to restrict unacked list entries.
- Ensure new entries are correctly added.
- Drop the last entry if the list exceeds the limit.
- Validate ack handling in batadv_tp_ack_unordered().
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-2026-63834.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63834 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-2026-63834
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-2026-63834 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63834 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.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 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': '33a3bb4a3345bb511f9c69c913da95d4693e2a4e', 'lessThan': '31a88792bfba142be3c9521538c1db805677381f', 'versionType': 'git'}, {'status': 'affected', 'version': '33a3bb4a3345bb511f9c69c913da95d4693e2a4e', 'lessThan': '1111a3381bca2d1f084a07686bc783af5ab23df7', 'versionType': 'git'}, {'status': 'affected', 'version': '33a3bb4a3345bb511f9c69c913da95d4693e2a4e', 'lessThan': '1c616b0be4bd8399d485e25e91859373b95d6013', 'versionType': 'git'}, {'status': 'affected', 'version': '33a3bb4a3345bb511f9c69c913da95d4693e2a4e', 'lessThan': 'f8c499fd275e59203b77fca76ae6ef2d096c2133', 'versionType': 'git'}, {'status': 'affected', 'version': '33a3bb4a3345bb511f9c69c913da95d4693e2a4e', 'lessThan': 'c6231d628d06d841bc1617b2f7034f5f39876b16', 'versionType': 'git'}, {'status': 'affected', 'version': '33a3bb4a3345bb511f9c69c913da95d4693e2a4e', 'lessThan': '2233787658db859f0a9b83cb397cf783bb8be865', 'versionType': 'git'}, {'status': 'affected', 'version': '33a3bb4a3345bb511f9c69c913da95d4693e2a4e', 'lessThan': '1fb8762600a393d1caccd63be5d07e1756982d68', 'versionType': 'git'}, {'status': 'affected', 'version': '33a3bb4a3345bb511f9c69c913da95d4693e2a4e', 'lessThan': 'e7c775110e1858e5a7471a23a9c9658c0af9df89', 'versionType': 'git'}], 'programFiles': ['net/batman-adv/tp_meter.c', 'net/batman-adv/types.h'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.8'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.8', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.260', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.211', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.177', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.144', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/batman-adv/tp_meter.c', 'net/batman-adv/types.h'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: batman-adv: tp_meter: restrict number of unacked list entries When the unacked_list is unbound, an attacker could send messages with small lengths and appropriated seqno + gaps to force the receiver to allocate more and more unacked_list entries. And the end either causing an out-of-memory situation or increase the management overhead for the (large) list that significant portions of CPU cycles are wasted in searching through the list. When limiting the list to a specific number, it is important to still correctly add a new entry to the list. But if the list became larger than the limit, the last entry of the list (with the highest seqno) must be dropped to still allow the earlier seqnos to finish and therefore to continue the process. Otherwise, the process might get stuck with too high seqnos which are not handled by batadv_tp_ack_unordered(). Added Reference https://git.kernel.org/stable/c/1111a3381bca2d1f084a07686bc783af5ab23df7 Added Reference https://git.kernel.org/stable/c/1c616b0be4bd8399d485e25e91859373b95d6013 Added Reference https://git.kernel.org/stable/c/1fb8762600a393d1caccd63be5d07e1756982d68 Added Reference https://git.kernel.org/stable/c/2233787658db859f0a9b83cb397cf783bb8be865 Added Reference https://git.kernel.org/stable/c/31a88792bfba142be3c9521538c1db805677381f Added Reference https://git.kernel.org/stable/c/c6231d628d06d841bc1617b2f7034f5f39876b16 Added Reference https://git.kernel.org/stable/c/e7c775110e1858e5a7471a23a9c9658c0af9df89 Added Reference https://git.kernel.org/stable/c/f8c499fd275e59203b77fca76ae6ef2d096c2133