CVE-2024-53206: Linux kernel · tcp: Fix use-after-free of nreq in reqsk_timer_handler().
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 5.15.0-1086.95~20.04.1 : patch Linux kernel as a priority.
Data as of 29 Oct 2026, 22:35 UTC
- Patch
- Available – fixed in 5.15.0-1086.95~20.04.1, 5.15.0-1081.90~20.04.1, 5.15.0-136.147~20.04.1 +21
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Dec 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7387-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7407-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7421-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7459-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7459-2 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinux-raspi-realtimepkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-allwinner-5.19pkg:deb/ubuntu/linux-allwinner-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-aws-5.19pkg:deb/ubuntu/linux-aws-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-6.2pkg:deb/ubuntu/linux-aws-6.2?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: tcp: Fix use-after-free of nreq in reqsk_timer_handler(). The cited commit replaced inet_csk_reqsk_queue_drop_and_put() with __inet_csk_reqsk_queue_drop() and reqsk_put() in reqsk_timer_handler(). Then, oreq should be passed to reqsk_put() instead of req; otherwise use-after-free of nreq could happen when reqsk is migrated but the retry attempt failed (e.g. due to timeout). Let's pass oreq to reqsk_put().
References
- ubuntu.com/security/CVE-2024-53206 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-53206 (opens in a new tab)
- git.kernel.org/linus/c31e72d021db2714df03df6c42855a1db592716c (opens in a new tab)
- git.kernel.org/stable/c/2dcc86fefe09ac853158afd96b60d544af115dc5 (opens in a new tab)
- git.kernel.org/stable/c/65ed89cad1f57034c256b016e89e8c0a4ec7c65b (opens in a new tab)
- git.kernel.org/stable/c/6d845028609a4af0ad66f499ee0bd5789122b067 (opens in a new tab)
- git.kernel.org/stable/c/9a3c1ad93e6fba67b3a637cfa95a57a6685e4908 (opens in a new tab)
- git.kernel.org/stable/c/c31e72d021db2714df03df6c42855a1db592716c (opens in a new tab)
- git.kernel.org/stable/c/d0eb14cb8c08b00c36a3d5dc57a6f428b301f721 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7407-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7421-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7459-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7459-2 (opens in a new tab)