Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Privileges required (PR:N) | No privileges required |
| User interaction (UI:N) | No user interaction |
| Scope (S:U) | Scope unchanged |
| Confidentiality (C:N) | No confidentiality impact |
| Integrity (I:N) | No integrity impact |
| Availability (A:H) | High availability impact |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
About Kamailio
CVE-2026-52023 affects Kamailio, a product from Kamailio. Before acting, confirm where Kamailio runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: An issue in kamailio v.6.1.1 and before allows a remote attacker to cause a denial of service via the ims_registrar_pcscf module, specifically the pcscf_save_pending/save_pending path and security-agreement parsing in sec_agree.c:parse_sec_agree()
The weakness class is Uncontrolled Resource Consumption. An attacker can exhaust CPU, memory or connections.
Based on its CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Kamailio |
| Affected versions | Kamailio up to and including 6.1.1 |
| Published | Sep 1, 2026 |
| Last modified | Sep 15, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | cve@mitre.org |
How to detect it
- Inventory every instance of Kamailio and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Kamailio named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Kamailio to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-415 More CVEs with this weakness
- CWE-400: Uncontrolled Resource Consumption More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
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A double free in the OpenSSL-based TLS certificate revocation checking path of the MongoDB C Driver can be reached by a TLS endpoint that the client already trusts. During the handshake, specially formed certificate data can cause the same heap object to be released twice. An unauthenticated party acting as the trusted endpoint may cause the connecting client application to terminate unexpectedly.
In the Linux kernel, the following vulnerability has been resolved: drm/xe/nvm: Fix double-free on aux add failure After a successful auxiliary_device_init(), aux_dev->dev.release (xe_nvm_release_dev()) is responsible for the kfree(nvm). When there is failure with auxiliary_device_add(), driver will call auxiliary_device_uninit(), which call put_device(). So that the .release callback will be triggered to free the memory associated with the auxiliary_device. Move the kfree(nvm) into the auxiliary_device_init() failure path and remove the err goto path to fix below error. " [ 13.232905] ================================================================== [ 13.232911] BUG: KASAN: double-free in xe_nvm_init+0x751/0xf10 [xe] [ 13.233112] Free of addr ffff888120635000 by task systemd-udevd/273 [ 13.233120] CPU: 8 UID: 0 PID: 273 Comm: systemd-udevd Not tainted 6.19.0-rc2-lgci-xe-kernel+ #225 PREEMPT(voluntary) ... [ 13.233125] Call Trace: [ 13.233126] <TASK> [ 13.233127] dump_stack_lvl+0x7f/0xc0 [ 13.233132] print_report+0xce/0x610 [ 13.233136] ? kasan_complete_mode_report_info+0x5d/0x1e0 [ 13.233139] ? xe_nvm_init+0x751/0xf10 [xe] ... " v2: drop err goto path. (Alexander) (cherry picked from commit a3187c0c2bbd947ffff97f90d077ac88f9c2a215)
In the Linux kernel, the following vulnerability has been resolved: pinctrl: cirrus: cs42l43: Fix double-put in cs42l43_pin_probe() devm_add_action_or_reset() already invokes the action on failure, so the explicit put causes a double-put.
In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Fix bsg_done() causing double free Kernel panic observed on system, [5353358.825191] BUG: unable to handle page fault for address: ff5f5e897b024000 [5353358.825194] #PF: supervisor write access in kernel mode [5353358.825195] #PF: error_code(0x0002) - not-present page [5353358.825196] PGD 100006067 P4D 0 [5353358.825198] Oops: 0002 [#1] PREEMPT SMP NOPTI [5353358.825200] CPU: 5 PID: 2132085 Comm: qlafwupdate.sub Kdump: loaded Tainted: G W L ------- --- 5.14.0-503.34.1.el9_5.x86_64 #1 [5353358.825203] Hardware name: HPE ProLiant DL360 Gen11/ProLiant DL360 Gen11, BIOS 2.44 01/17/2025 [5353358.825204] RIP: 0010:memcpy_erms+0x6/0x10 [5353358.825211] RSP: 0018:ff591da8f4f6b710 EFLAGS: 00010246 [5353358.825212] RAX: ff5f5e897b024000 RBX: 0000000000007090 RCX: 0000000000001000 [5353358.825213] RDX: 0000000000001000 RSI: ff591da8f4fed090 RDI: ff5f5e897b024000 [5353358.825214] RBP: 0000000000010000 R08: ff5f5e897b024000 R09: 0000000000000000 [5353358.825215] R10: ff46cf8c40517000 R11: 0000000000000001 R12: 0000000000008090 [5353358.825216] R13: ff591da8f4f6b720 R14: 0000000000001000 R15: 0000000000000000 [5353358.825218] FS: 00007f1e88d47740(0000) GS:ff46cf935f940000(0000) knlGS:0000000000000000 [5353358.825219] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [5353358.825220] CR2: ff5f5e897b024000 CR3: 0000000231532004 CR4: 0000000000771ef0 [5353358.825221] PKRU: 55555554 [5353358.825222] Call Trace: [5353358.825223] <TASK> [5353358.825224] ? show_trace_log_lvl+0x1c4/0x2df [5353358.825229] ? show_trace_log_lvl+0x1c4/0x2df [5353358.825232] ? sg_copy_buffer+0xc8/0x110 [5353358.825236] ? __die_body.cold+0x8/0xd [5353358.825238] ? page_fault_oops+0x134/0x170 [5353358.825242] ? kernelmode_fixup_or_oops+0x84/0x110 [5353358.825244] ? exc_page_fault+0xa8/0x150 [5353358.825247] ? asm_exc_page_fault+0x22/0x30 [5353358.825252] ? memcpy_erms+0x6/0x10 [5353358.825253] sg_copy_buffer+0xc8/0x110 [5353358.825259] qla2x00_process_vendor_specific+0x652/0x1320 [qla2xxx] [5353358.825317] qla24xx_bsg_request+0x1b2/0x2d0 [qla2xxx] Most routines in qla_bsg.c call bsg_done() only for success cases. However a few invoke it for failure case as well leading to a double free. Validate before calling bsg_done().
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