CVE-2026-23021: Linux kernel · net: usb: pegasus: fix memory leak in update_eth_regs_async()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1103.110~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1103.110~20.04.1, 5.15.0-1110.119~20.04.1, 5.15.0-1103.112~20.04.1 +57
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 31 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1018.18?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied by updating the Linux kernel to the fixed versions as provided by the vendor (Ubuntu). After applying the update, a system reboot is required to complete remediation. Due to an ABI change, third-party kernel modules must be recompiled and reinstalled. Follow the vendor advisory instructions for updating to the appropriate patched kernel package versions. No additional mitigation is indicated beyond applying the official fix.
Description
A memory leak vulnerability in the Linux kernel's USB Pegasus network driver (update_eth_regs_async function) was identified and fixed. The issue occurs when usb_submit_urb() fails during asynchronous register writes, causing allocated resources not to be released. This flaw could lead to denial of service by exhausting system memory. The vulnerability has a medium severity with a CVSS score of 5.5. Multiple Linux kernel versions prior to specific 5.15.x updates are affected. Ubuntu has released patches addressing this and other kernel vulnerabilities, requiring system updates and reboots to apply fixes.
References
- ubuntu.com/security/CVE-2026-23021 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23021 (opens in a new tab)
- git.kernel.org/linus/afa27621a28af317523e0836dad430bec551eb54 (opens in a new tab)
- git.kernel.org/stable/c/471dfb97599eec74e0476046b3ef8e7037f27b34 (opens in a new tab)
- git.kernel.org/stable/c/5397ea6d21c35a17707e201a60761bdee00bcc4e (opens in a new tab)
- git.kernel.org/stable/c/93f18eaa190374e0f2d253e3b1a65cee19a7abe6 (opens in a new tab)
- git.kernel.org/stable/c/a40af9a2904a1ab8ce61866ebe2a894ef30754ba (opens in a new tab)
- git.kernel.org/stable/c/ac5d92d2826dec51e5d4c6854865bc5817277452 (opens in a new tab)
- git.kernel.org/stable/c/afa27621a28af317523e0836dad430bec551eb54 (opens in a new tab)
- git.kernel.org/stable/c/ce6eef731aba23a988decea1df3b08cf978f7b01 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8116-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8096-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8141-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8163-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8163-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8243-1 (opens in a new tab)