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NVD / CVE Program· CNA Linux

CVE-2026-93228: svcrdma: Reject Write/Reply chunks with segcount 0

Noroxi assessment

Priority: Monitor (action score 36/100)

  • 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: 0.50% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 28c5a3a572f6cf81ac304459cfd515480995d62a, 45dbdb2637b7fc5f1355b588780d2a7fb0516805, 9808eb7656666acc7291bae9ab6b987bd16e47e0; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 6.6.161.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 28c5a3a572f6cf81ac304459cfd515480995d62a, 45dbdb2637b7fc5f1355b588780d2a7fb0516805, 9808eb7656666acc7291bae9ab6b987bd16e47e0; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.159.1-1 on Azure Linux 3.0 6.6.161.1-1 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: svcrdma: Reject Write/Reply chunks with segcount 0 A peer can send a Write or Reply chunk whose segcount field is zero. xdr_check_write_chunk() only rejects segcount > rc_maxpages, so zero passes the range check, and xdr_inline_decode(stream, 0) returns the current (non-NULL) cursor without advancing. The function returns true and pcl_alloc_write() then links a struct svc_rdma_chunk with ch_segcount == 0 onto rc_write_pcl or rc_reply_pcl. An earlier patch in this series made pcl_for_each_segment() safe for ch_segcount == 0, so this no longer drives the memory walk it used to. Rejecting the malformed frame at the decode boundary is still worthwhile as defense in depth: it keeps degenerate zero-segment chunks off the parsed chunk lists entirely, so any future consumer that walks ch_segments directly cannot observe one, and it makes the zero-floor easy to backport to trees where the macro change is more intrusive. RFC 8166 has no meaning for a Write/Reply chunk that describes no remote buffer, so no legitimate client is affected. xdr_check_reply_chunk() funnels Reply chunks through xdr_check_write_chunk() and inherits the same rejection. pcl_alloc_write() also links each chunk onto the parsed chunk list before filling its segment array. If a future change weakens the segcount-0 rejection, an incomplete chunk is visible to consumers during the fill loop. Reorder so that list_add_tail() follows the segment fill loop, ensuring only fully-populated chunks appear on the list.

CriticalCVSS 9.1 · v3.1—No exploit Fix available
Published
Sep 24, 2026
Updated
Oct 30, 2026
EPSS
0.5% · 43th percentile
CWE
—

Report tools

JSON

Action score

36

Monitor

Low priority for now.

CVSS
36 / 40 · 9.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CNA vs NVD score

NVD
—
CNA · Linux
9.1
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?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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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.

—

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

    • 5.11affected
    • 78147ca8b4a9b6cf0e597ddd6bf17959e08376c2 and later · before ac730b8cbaeec6831116e1455d909ecbdcdcbd34affected · git
    • 78147ca8b4a9b6cf0e597ddd6bf17959e08376c2 and later · before 28c5a3a572f6cf81ac304459cfd515480995d62aaffected · git
    • 78147ca8b4a9b6cf0e597ddd6bf17959e08376c2 and later · before fe533ae1bed2ef2b3d54ee7ab410da1874ed3d4faffected · git
    • 78147ca8b4a9b6cf0e597ddd6bf17959e08376c2 and later · before a798714b58041e88716db3bf8fb03ae13eecd54aaffected · git
    • 78147ca8b4a9b6cf0e597ddd6bf17959e08376c2 and later · before 45dbdb2637b7fc5f1355b588780d2a7fb0516805affected · git
    • 78147ca8b4a9b6cf0e597ddd6bf17959e08376c2 and later · before 9808eb7656666acc7291bae9ab6b987bd16e47e0affected · git
    • before 5.11not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.160 and later · up to and including 6.6.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.66.1.el10_26.12.0-211.66.1.el10_2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-93226Sep 24, 2026 · ipv6: use RCU iterator to dump route exceptions
    0Monitor
  • ← EarlierCVE-2026-93227Sep 24, 2026 · mm/mm_init: deferred_grow_zone(): fix out-of-range first_deferred_pfn
    0Monitor
  • Later →CVE-2026-93229Sep 24, 2026 · nfsd: add missing read barrier to rpc_status_get dumpit seqcount retry
    28Monitor

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 Linux28c5a3a572f6cf81ac304459cfd515480995d62aVendor (CNA)
Linux Linux45dbdb2637b7fc5f1355b588780d2a7fb0516805Vendor (CNA)
Linux Linux9808eb7656666acc7291bae9ab6b987bd16e47e0Vendor (CNA)
Linux Linuxa798714b58041e88716db3bf8fb03ae13eecd54aVendor (CNA)
Linux Linuxac730b8cbaeec6831116e1455d909ecbdcdcbd34Vendor (CNA)
Linux Linuxfe533ae1bed2ef2b3d54ee7ab410da1874ed3d4fVendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.06.6.161.1-1 · Release NotesMicrosoft (MSRC)
almalinux:bpftool4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-core5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-core5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-core5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-64k-devel-matched5.14.0-687.58.1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.174.1.el8_10 · AlmaLinux:8Package registry (OSV)

+18

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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • 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
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/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.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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

References

Show all references (5 more)

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

All records