CVE-2026-23356
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
A logic bug was fixed in the Linux kernel's DRBD drbd_al_begin_io_nonblock() function. Under certain race conditions, lc_get_cumulative() could fail despite a prior check indicating success, logging "LOGIC BUG" without returning an error. This broke mutual exclusivity between resync and application I/O and could trigger BUG_ON(refcnt == 0) in lc_put().
Risk Assessment
During an active DRBD resync, resync and application I/O may conflict, risking data corruption or a kernel crash (BUG_ON). In clustered environments using DRBD replication, this may cause service unavailability.
Recommendation
Update the Linux kernel to a version containing the fix for CVE-2026-23356. If immediate update is not possible, consider pausing DRBD resync operations during critical maintenance windows.
Related vulnerabilities
- CVE-2026-124060Critical
A vulnerability was detected in TOTOLINK CA300-PoE version 6.2c.884 in the UploadCustomModule function of the file /cgi-bin/cstecgi.cgi. Manipulation of the File argument results in a buffer overflow. The attack can be launched remotely, and the exploit is now public and may be used.
- CVE-2026-124059Critical
A security vulnerability has been detected in TOTOLINK CA300-PoE 6.2c.884. The function setWiFiWdsAddConfig in the file /cgi-bin/cstecgi.cgi is affected, where manipulation of the ApCliKeyStr argument leads to a buffer overflow. The attack may be initiated remotely, and the exploit has been disclosed publicly and may be used.
- CVE-2026-124058Critical
A weakness has been identified in TOTOLINK CA300-PoE 6.2c.884. The function setWiFiRepeaterConfig in the file /cgi-bin/cstecgi.cgi is affected, where manipulation of the ApCliKeyStr argument can lead to a buffer overflow. The attack can be launched remotely, and the exploit has been made available to the public and could be used for attacks.
- CVE-2026-124057Critical
A security flaw has been discovered in TOTOLINK CA300-PoE 6.2c.884. This impacts the function setWiFiMultipleConfig of the file /cgi-bin/cstecgi.cgi. Manipulation of the argument Key1Str1 results in a buffer overflow. The attack can be initiated remotely. The exploit has been released to the public and may be used for attacks.
- CVE-2026-123966Critical
A vulnerability was found in Tenda AC19 version 16.03.10.07 in the saveParentControlInfo function of the /goform/saveParentControlInfo file. Manipulating the deviceId argument causes a heap-based buffer overflow. The attack can be carried out remotely, and the exploit has been publicly disclosed.
- CVE-2026-120984Critical
A flaw was found in the Keycloak server's client management component. When a client is created or imported with authorization services enabled, the system fails to properly clear an internal session attribute used during setup. An authenticated attacker with client management permissions can bypass security controls and upload a malicious JavaScript policy that executes on the server.
- CVE-2026-122041Critical
The Checkout Field Editor for WooCommerce (Pro) plugin for WordPress up to and including 3.8.0 is vulnerable to unauthorized deletion of arbitrary attachments due to a missing capability/ownership check in the ajax_remove_uploaded() function. The handler is registered for both wp_ajax and wp_ajax_nopriv and gated solely by the 'file_handling_nonce' nonce, which is exposed in the public checkout page markup.
- CVE-2026-119075Critical
The Registration Form for WooCommerce plugin for WordPress is vulnerable to privilege escalation due to a missing allow-list check in FormHandler::validate_checkout_fields() in versions up to and including 1.1.4. The checkout registration path stores the raw $_POST['user_roles'] value without validation, and add_user_data() injects it as the new account's role.
- CVE-2026-118066Critical
The LatePoint plugin for WordPress is vulnerable to authentication bypass via account takeover in versions up to and including 5.7.6. OsModel::build_conditions_query() compares WHERE-clause values against literal strings 'IS NULL' and 'IS NOT NULL' and concatenates a match directly into SQL without binding, allowing unauthenticated attackers to send params[password_reset_token]=IS NOT NULL to the public customer_cabinet__change_password AJAX route and overwrite the lowest-id customer's password.
- CVE-2026-104014Critical
The Naimur Email OTP Verification for WooCommerce plugin is vulnerable to authentication bypass in versions up to and including 2.1.0. The password-reset finalization endpoint authorizes the reset solely by the presence of a database row marking an email as 'VERIFIED', with no timestamp check, session binding, or per-reset token, and the scheduled cleanup cron has no handler so it never runs.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: drbd: fix "LOGIC BUG" in drbd_al_begin_io_nonblock() Even though we check that we "should" be able to do lc_get_cumulative() while holding the device->al_lock spinlock, it may still fail, if some other code path decided to do lc_try_lock() with bad timing. If that happened, we logged "LOGIC BUG for enr=...", but still did not return an error. The rest of the code now assumed that this request has references for the relevant activity log extents. The implcations are that during an active resync, mutual exclusivity of resync versus application IO is not guaranteed. And a potential crash at this point may not realizs that these extents could have been target of in-flight IO and would need to be resynced just in case. Also, once the request completes, it will give up activity log references it does not even hold, which will trigger a BUG_ON(refcnt == 0) in lc_put(). Fix: Do not crash the kernel for a condition that is harmless during normal operation: also catch "e->refcnt == 0", not only "e == NULL" when being noisy about "al_complete_io() called on inactive extent %u\n". And do not try to be smart and "guess" whether something will work, then be surprised when it does not. Deal with the fact that it may or may not work. If it does not, remember a possible "partially in activity log" state (only possible for requests that cross extent boundaries), and return an error code from drbd_al_begin_io_nonblock(). A latter call for the same request will then resume from where we left off.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

