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CVE Record

CVE-2026-43494: net/rds: reset op_nents when zerocopy page pin fails

In the Linux kernel, the following vulnerability has been resolved: net/rds: reset op_nents when zerocopy page pin fails When iov_iter_get_pages2() fails in rds_message_zcopy_from_user(), the pinned pages are released with put_page(), and rm->data.op_mmp_znotifier is cleared. But we fail to properly clear rm->data.op_nents. Later when rds_message_purge() is called from rds_sendmsg() the cleanup loop iterates over the incorrectly non zero number of op_nents and frees them again. Fix this by properly resetting op_nents when it should be in rds_message_zcopy_from_user().

HighCVSS 7.8Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2026-43494 is a Linux kernel memory-cleanup flaw in the RDS networking code. A local user can trigger an error path that may free the same pages twice, risking system compromise or crash. The source rates it high with CVSS 7.8.

Executive priority

Treat as a high-priority kernel update for systems allowing local users or untrusted workloads. It is not described as remotely exploitable, but successful exploitation could affect confidentiality, integrity, and availability of the host.

Technical view

In net/rds, rds_message_zcopy_from_user() releases pinned pages when iov_iter_get_pages2() fails, but does not reset rm->data.op_nents. Later rds_message_purge() can iterate stale entries and free them again. The issue maps to CWE-1341 and is local, low-complexity, privileged-user reachable.

Likely exposure

Exposure is most likely on Linux systems running affected kernel builds where the RDS zero-copy send path is available to local users. Distribution impact depends on kernel configuration and vendor backports; the bundle does not prove every listed version is exploitable in every environment.

Exploitation context

The CVSS vector is local with low complexity and low privileges, no user interaction. The source bundle says KEV is false, so active exploitation is not established. A public PoC repository is referenced, but the bundle provides no validated exploitation status.

Researcher notes

The key bug condition is failed page pinning in the RDS zero-copy path leaving op_nents stale after cleanup. Validate against vendor source or stable commit backports, because distribution kernels may carry fixes without matching upstream version numbers.

Mitigation direction

  • Apply Linux kernel stable or distribution vendor updates for CVE-2026-43494.
  • Check Red Hat or your Linux vendor advisory for affected package status.
  • Prioritize multi-user servers, shared compute, and container hosts first.
  • If patching is delayed, review vendor guidance for RDS-specific mitigations.

Validation and detection

  • Inventory Linux kernel versions and vendor package advisory status.
  • Confirm whether RDS support is present or enabled on exposed hosts.
  • Check whether installed kernels include the referenced stable commits.
  • Review local-user access on affected systems while remediation is pending.
Prepared
Confidence
medium
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-1341: Exact CWE lookup

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cve · low confidence lookup

CVE-2026-43494 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.8 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
13Source links

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux
7CVSS 3.1HighCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H15.9redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2026-43494Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Reported to Red Hat.

  3. ADP timelineredhat-SADP

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CVECVE Program Container
redhat-SADPkernel: net/rds: reset op_nents when zerocopy page pin fails
other:Red Hat severity ratingcvssV3_1
  • 2026-05-21T00:00:00.000Z: Reported to Red Hat.
  • 2026-05-21T00:00:00.000Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3, 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3, 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3, 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3, 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3, 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3, 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3, 0cebaccef3acbdfbc2d85880a2efb765d2f4e2e3unaffected
LinuxLinux4.17, 0, 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1affected
Weakness

CWE details

CWE-1341

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-1341 · source CWE mapping

Multiple Releases of Same Resource or Handle

Multiple Releases of Same Resource or Handle represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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