CVE-2025-39894 Vulnerability Analysis & Exploit Details

CVE-2025-39894
Vulnerability Scoring

Analysis In Progress
Analysis In Progress

Attack Complexity Details

  • Attack Complexity:
    Attack Complexity Analysis In Progress
  • Attack Vector:
    Attack Vector Under Analysis
  • Privileges Required: None
    No authentication is required for exploitation.
  • Scope:
    Impact is confined to the initially vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2025-39894 Details

Status: Awaiting Analysis

Last updated: 🕖 02 Oct 2025, 19:12 UTC
Originally published on: 🕗 01 Oct 2025, 08:15 UTC

Time between publication and last update: 1 days

CVSS Release:

CVE-2025-39894 Vulnerability Summary

CVE-2025-39894: In the Linux kernel, the following vulnerability has been resolved: netfilter: br_netfilter: do not check confirmed bit in br_nf_local_in() after confirm When send a broadcast packet to a tap device, which was added to a bridge, br_nf_local_in() is called to confirm the conntrack. If another conntrack with the same hash value is added to the hash table, which can be triggered by a normal packet to a non-bridge device, the below warning may happen. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 96 at net/bridge/br_netfilter_hooks.c:632 br_nf_local_in+0x168/0x200 CPU: 1 UID: 0 PID: 96 Comm: tap_send Not tainted 6.17.0-rc2-dirty #44 PREEMPT(voluntary) RIP: 0010:br_nf_local_in+0x168/0x200 Call Trace: <TASK> nf_hook_slow+0x3e/0xf0 br_pass_frame_up+0x103/0x180 br_handle_frame_finish+0x2de/0x5b0 br_nf_hook_thresh+0xc0/0x120 br_nf_pre_routing_finish+0x168/0x3a0 br_nf_pre_routing+0x237/0x5e0 br_handle_frame+0x1ec/0x3c0 __netif_receive_skb_core+0x225/0x1210 __netif_receive_skb_one_core+0x37/0xa0 netif_receive_skb+0x36/0x160 tun_get_user+0xa54/0x10c0 tun_chr_write_iter+0x65/0xb0 vfs_write+0x305/0x410 ksys_write+0x60/0xd0 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> ---[ end trace 0000000000000000 ]--- To solve the hash conflict, nf_ct_resolve_clash() try to merge the conntracks, and update skb->_nfct. However, br_nf_local_in() still use the old ct from local variable 'nfct' after confirm(), which leads to this warning. If confirm() does not insert the conntrack entry and return NF_DROP, the warning may also occur. There is no need to reserve the WARN_ON_ONCE, just remove it.

Assessing the Risk of CVE-2025-39894

Access Complexity Graph

The exploitability of CVE-2025-39894 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2025-39894

No exploitability data is available for CVE-2025-39894.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2025-39894, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2025-39894, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2025-39894 does not compromise confidentiality.
  • Integrity: None
    CVE-2025-39894 does not impact data integrity.
  • Availability: None
    CVE-2025-39894 does not affect system availability.

CVE-2025-39894 References

External References

CWE Common Weakness Enumeration

Unknown

Protect Your Infrastructure against CVE-2025-39894: Combat Critical CVE Threats

Stay updated with real-time CVE vulnerabilities and take action to secure your systems. Enhance your cybersecurity posture with the latest threat intelligence and mitigation techniques. Develop the skills necessary to defend against CVEs and secure critical infrastructures. Join the top cybersecurity professionals safeguarding today's infrastructures.

Other 5 Recently Published CVEs Vulnerabilities

  • CVE-2025-11939 – A vulnerability was determined in ChurchCRM up to 5.18.0. This issue affects some unknown processing of the file src/ChurchCRM/Backup/RestoreJob.ph...
  • CVE-2025-11938 – A vulnerability was found in ChurchCRM up to 5.18.0. This vulnerability affects unknown code of the file setup/routes/setup.php. Performing manipul...
  • CVE-2025-62672 – rplay through 3.3.2 allows attackers to cause a denial of service (SIGSEGV and daemon crash) or possibly have unspecified other impact. This occurs...
  • CVE-2025-47410 – Apache Geode is vulnerable to CSRF attacks through GET requests to the Management and Monitoring REST API that could allow an attacker who has tric...
  • CVE-2025-11926 – The Related Posts Lite plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in all versions up to, and including, 1...