Use After FreeWeakness · CWE-416

CVE-2025-13350

HIGH · 7.1 CVSS v4.0 Published 2026-03-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
73/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Ubuntu Linux 6.8 GA retains the legacy AF_UNIX garbage collector but backports upstream commit 8594d9b85c07 ("af_unix: Don’t call skb_get() for OOB skb"). When orphaned MSG_OOB sockets hit unix_gc(), the garbage collector still calls kfree_skb() as if OOB SKBs held two references; on Ubuntu Linux 6.8 (Noble Numbat) kernel tree, they have only the queue reference, so the buffer is freed while still reachable and subsequent queue walks dereference freed memory, yielding a reliable local privilege escalation (LPE) caused by a use-after-free (UAF). Ubuntu builds that have already taken the new GC stack from commit 4090fa373f0e, and mainline Linux kernels shipping that infrastructure are unaffected because they no longer execute the legacy collector path. This issue affects Ubuntu Linux from 6.8.0-56.58 before 6.8.0-84.84.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Use-after-free vulnerability in Ubuntu Linux 6.8's AF_UNIX garbage collector where the legacy GC calls kfree_skb() on orphaned MSG_OOB sockets as if they hold two references, when they actually only hold one. This causes premature buffer freeing while still reachable, leading to UAF during subsequent queue walks and enabling local privilege escalation.

MitigationUpgrade Ubuntu Linux kernel to version 6.8.0-84.84 or later. Systems with the new GC stack from commit 4090fa373f0e are unaffected.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
High
Privileges
Low
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Ubuntu Linux distribution
    Run `lsb_release -a` or check `/etc/os-release` to verify the OS is Ubuntu
    Affected if The system is not Ubuntu Linux (this CVE only affects Ubuntu)
  2. Check kernel version
    Run `uname -r` to get the running kernel version
    Affected if Kernel version is 6.8.x but earlier than 6.8.0-84.84 (or if version cannot be determined but appears to be in the 6.8 release series)
  3. Verify AF_UNIX socket support
    Check that AF_UNIX sockets are available by confirming CONFIG_UNIX in kernel config: `zcat /proc/config.gz 2>/dev/null | grep CONFIG_UNIX || grep -i unix /boot/config-$(uname -r) 2>/dev/null`
    Affected if AF_UNIX is enabled and the kernel version is in the vulnerable 6.8 range before 6.8.0-84.84

The environment is affected if running Ubuntu Linux with a 6.8 series kernel earlier than 6.8.0-84.84 and AF_UNIX socket support is enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Ubuntu Linux kernel to version 6.8.0-84.84 or later. Systems with the new GC stack from commit 4090fa373f0e are unaffected.

Recommended fix High confidence

Ubuntu Linux 6.8.0-84.84 or later (Noble Numbat kernel)

  1. Check current kernel version: uname -r
  2. Update package lists: sudo apt update
  3. Upgrade to latest kernel: sudo apt upgrade linux-image-generic
  4. Reboot the system: sudo reboot
  5. Verify the new kernel version after reboot: uname -r (should be 6.8.0-84.84 or later)
Caveat Kernel upgrades require system reboot; ensure proper downtime planning and backup of critical data before upgrading production systems

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,600
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-13350 in production — separate from our analysis above.

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What this is

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