CVE-2026-43492: Linux kernel · lib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +74
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 19 May 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 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 to affected linux-aws kernel versions. The vendor advisory from Ubuntu confirms that this issue is fixed in updated kernel releases. Users should upgrade to a fixed kernel version to remediate this vulnerability.
Description
An integer underflow vulnerability in the Linux kernel's cryptographic MPI library (mpi_read_raw_from_sgl function) can cause a denial of service (DoS) via a kernel soft lockup. This occurs when a crafted scatterlist with more bytes than the specified nbytes and filled with zeroes triggers an infinite loop. The flaw affects specific linux-aws kernel versions and was introduced by a commit changing how scatterlists are used. The issue is fixed in updated kernel releases.
References
- ubuntu.com/security/CVE-2026-43492 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43492 (opens in a new tab)
- git.kernel.org/linus/8c2f1288250a90a4b5cabed5d888d7e3aeed4035 (opens in a new tab)
- git.kernel.org/stable/c/26d3a97ad46c7a9226ec04d4bf35bd4998a97d16 (opens in a new tab)
- git.kernel.org/stable/c/2aa77a18dc7f2670497fe3ee5acbeda0b57659e5 (opens in a new tab)
- git.kernel.org/stable/c/30e513e755bb381afce6fb57cdc8694136193f22 (opens in a new tab)
- git.kernel.org/stable/c/8637dfb4c1d8a7026ef681f2477c6de8b71c4003 (opens in a new tab)
- git.kernel.org/stable/c/8c2f1288250a90a4b5cabed5d888d7e3aeed4035 (opens in a new tab)
- ubuntu.com/security/notices/USN-8566-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8568-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8569-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8606-1 (opens in a new tab)