CVE-2025-40279

EPSS 0.1%
  • Published: 2025-12-06T22:15:55.843

In the Linux kernel, the following vulnerability has been resolved:

net: sched: act_connmark: initialize struct tc_ife to fix kernel leak

In tcf_connmark_dump(), the variable ‘opt’ was partially initialized using a
designatied initializer. While the padding bytes are reamined
uninitialized. nla_put() copies the entire structure into a
netlink message, these uninitialized bytes leaked to userspace.

Initialize the structure with memset before assigning its fields
to ensure all members and padding are cleared prior to beign copied.

Related CVE by CWE

No related CWE found.

Top CVE for Vendor

No vendor taxonomy on this entry.

Recently Exploited Similar Vulnerabilities

No recent KEV-listed items for this vendor/product.

How to fix CVE-2025-40279

CVE-2025-40279 is a unknown severity vulnerability affecting the affected product.

Description: In the Linux kernel, the following vulnerability has been resolved: net: sched: act_connmark: initialize struct tc_ife to fix kernel leak In tcf_connmark_dump(), the variable ‘opt’ was partially initialized using a designatied initializer. While the padding bytes are reamined uninitialized. nla_put() copies the entire structure into a netlink message, these uninitialized bytes leaked to userspace. Initialize […]

Exploit Difficulty: HARD
⏱️ Time to exploit: > 4 hours
🛠️ Required skills: Advanced security expertise
💰 Public exploits: Rare or not public

How to Fix:

1 Identify affected systems

- Check if you're running the affected product

2 Immediate actions

- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access

3 Verification

- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)

4 Long-term prevention

- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations

Exploit Difficulty Assessment

HARD
⏱️ Time to Exploit: > 4 hours
🛠️ Skills Required: Advanced security expertise
💰 Public Exploits: Rare or not public

Vulnerability Timeline

Dec 06, 2025
Vulnerability Published

CVE details first published to NVD database

Dec 06, 2025
Imported to Database

Added to this CVE tracking system

Detection Rules & IOCs

No specific detection rules generated for this vulnerability type.

No vendor/product data available.