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NVD / CVE Program· CNA Linux

CVE-2026-45856: RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send

Noroxi assessment

Priority: Monitor (action score 28/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.18% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 01c9b152647dc70dc06a4a2eff86ebb3b3c76075, 1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0, 9b5ac1c15334d46c0dbd49d64a2257b929500163.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 01c9b152647dc70dc06a4a2eff86ebb3b3c76075, 1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0, 9b5ac1c15334d46c0dbd49d64a2257b929500163 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send ib_uverbs_post_send() uses cmd.wqe_size from userspace without any validation before passing it to kmalloc() and using the allocated buffer as struct ib_uverbs_send_wr. If a user provides a small wqe_size value (e.g., 1), kmalloc() will succeed, but subsequent accesses to user_wr->opcode, user_wr->num_sge, and other fields will read beyond the allocated buffer, resulting in an out-of-bounds read from kernel heap memory. This could potentially leak sensitive kernel information to userspace. Additionally, providing an excessively large wqe_size can trigger a WARNING in the memory allocation path, as reported by syzkaller. This is inconsistent with ib_uverbs_unmarshall_recv() which properly validates that wqe_size >= sizeof(struct ib_uverbs_recv_wr) before proceeding. Add the same validation for ib_uverbs_post_send() to ensure wqe_size is at least sizeof(struct ib_uverbs_send_wr).

HighCVSS 7.1 · v3.1—No exploit Fix available
Published
May 27, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 8th percentile

Report tools

JSON

Action score

28

Monitor

Low priority for now.

CVSS
28 / 40 · 7.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.1
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.0 and later · before 5.10.252
  • linux linux kernel5.11 and later · before 5.15.202
  • linux linux kernel5.16 and later · before 6.1.165
  • linux linux kernel6.2 and later · before 6.6.128
  • linux linux kernel6.7 and later · before 6.12.75
  • linux linux kernel6.13 and later · before 6.18.14
  • linux linux kernel6.19 and later · before 6.19.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.0affected
    • c3bea3d2dc5358e05541527283279102383b0231 and later · before 9c15ec4cd4e7f57c6bbcb4e73e99290f150dd2a7affected · git
    • c3bea3d2dc5358e05541527283279102383b0231 and later · before 9b5ac1c15334d46c0dbd49d64a2257b929500163affected · git
    • c3bea3d2dc5358e05541527283279102383b0231 and later · before 01c9b152647dc70dc06a4a2eff86ebb3b3c76075affected · git
    • c3bea3d2dc5358e05541527283279102383b0231 and later · before bf1feed1a7886af945f92890493aefd2b5c9928aaffected · git
    • c3bea3d2dc5358e05541527283279102383b0231 and later · before d533425ac1f2925b4fc3e4ed9b9d72362cb23475affected · git
    • c3bea3d2dc5358e05541527283279102383b0231 and later · before bf4454da8b1e712714628c0a0d6e7845bb40790aaffected · git
    • c3bea3d2dc5358e05541527283279102383b0231 and later · before bef70ff9841990658610512b4a18e4a88c9b4df6affected · git
    • c3bea3d2dc5358e05541527283279102383b0231 and later · before 1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0affected · git
    • before 5.0not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.63.1.el10_26.12.0-211.63.1.el10_2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-45852May 27, 2026 · RDMA/rxe: Fix double free in rxe_srq_from_init
    31Monitor
  • ← EarlierCVE-2026-45855May 27, 2026 · ata: libata-scsi: avoid Non-NCQ command starvation
    22Monitor
  • Later →CVE-2026-45859May 27, 2026 · netfilter: nfnetlink_queue: do shared-unconfirmed check before segmentation
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux01c9b152647dc70dc06a4a2eff86ebb3b3c76075Vendor (CNA)
Linux Linux1956f0a74ccf5dc9c3ef717f2985c3ed3400aab0Vendor (CNA)
Linux Linux9b5ac1c15334d46c0dbd49d64a2257b929500163Vendor (CNA)
Linux Linux9c15ec4cd4e7f57c6bbcb4e73e99290f150dd2a7Vendor (CNA)
Linux Linuxbef70ff9841990658610512b4a18e4a88c9b4df6Vendor (CNA)
Linux Linuxbf1feed1a7886af945f92890493aefd2b5c9928aVendor (CNA)
Linux Linuxbf4454da8b1e712714628c0a0d6e7845bb40790aVendor (CNA)
Linux Linuxd533425ac1f2925b4fc3e4ed9b9d72362cb23475Vendor (CNA)
almalinux:kernel5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-687.54.1.el9_8 · AlmaLinux:9Package registry (OSV)
debian:linux6.1.170-1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:5.14.0-687.54.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel0:5.14.0-687.54.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debug-devel-matched0:5.14.0-687.54.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-debuginfo0:5.14.0-687.54.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel0:5.14.0-687.54.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-64k-devel-matched0:5.14.0-687.54.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-debuginfo0:5.14.0-687.54.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel0:5.14.0-687.54.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:kernel-debug-devel-matched0:5.14.0-687.54.1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)

+5

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records