CVE-2026-53133: Linux kernel · RDMA/umem: Fix truncation for block sizes >= 4G
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in dee2a49adeeb2a5e16a3fc858fa21b841c519802 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in dee2a49adeeb2a5e16a3fc858fa21b841c519802, cc644d5608e3b0dadc970bd6e6aa26b91ea07d0f, baf8685bcf56dc1efb44b8f6a57c42516e549068 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jun 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 |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: RDMA/umem: Fix truncation for block sizes >= 4G When the iommu is used the linearization of the mapping can give a single block that is very large split across multiple SG entries. When __rdma_block_iter_next() reassembles the split SG entries it is overflowing the 32 bit stack values and computed the wrong DMA addresses for blocks after the truncation. Use the right types to hold DMA addresses.
References
- git.kernel.org/stable/c/2ff4b7817e5b78070c30f5fb5e678e452a2628b3 (opens in a new tab)
- git.kernel.org/stable/c/dee2a49adeeb2a5e16a3fc858fa21b841c519802 (opens in a new tab)
- git.kernel.org/stable/c/cc644d5608e3b0dadc970bd6e6aa26b91ea07d0f (opens in a new tab)
- git.kernel.org/stable/c/8fe0231adebe086c8a459c790944ac026cd99c6e (opens in a new tab)
- git.kernel.org/stable/c/baf8685bcf56dc1efb44b8f6a57c42516e549068 (opens in a new tab)
- git.kernel.org/stable/c/afd35fec9297195b759078745549c2671223f24f (opens in a new tab)
- git.kernel.org/stable/c/ac1aad8e1281534ce936c250f68084fc79c5469e (opens in a new tab)
- git.kernel.org/stable/c/15fe76e23615f502d051ef0768f86babaf08746c (opens in a new tab)