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NVD / CVE Program· CNA Linux

CVE-2026-98127: smb/client: validate new EOF for insert range

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.13% (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 1519dc88c87f5346dae0464d7d6da1b6bf1f6e8e, 7c2c69045aa76ccaa7f16f1478eb312130ce4951, b7f2e33d9f5db7b8e6e5e0a5a93d0c5e31870356; 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 1519dc88c87f5346dae0464d7d6da1b6bf1f6e8e, 7c2c69045aa76ccaa7f16f1478eb312130ce4951, b7f2e33d9f5db7b8e6e5e0a5a93d0c5e31870356; 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: smb/client: validate new EOF for insert range smb3_insert_range() does not check if the new file size (i_size + len) is valid. This allows FALLOC_FL_INSERT_RANGE to bypass RLIMIT_FSIZE, exceed s_maxbytes, or produce a size outside the loff_t range. Use check_add_overflow() to calculate the new EOF. Validate it with inode_newsize_ok() before modifying the file. Reproducer, using a file on a CIFS mount: bash -c ' FILE=/mnt/cifs/repro trap "" SIGXFSZ ulimit -f 3072 # RLIMIT_FSIZE = 3 MiB # A regular write is stopped at 3 MiB. dd if=/dev/zero of="$FILE" bs=1M count=4 status=none stat -c "size after write: %s" "$FILE" # Insert 2 MiB into a 2 MiB file. truncate -s 2M "$FILE" fallocate -i -o 0 -l 2M "$FILE" stat -c "size after insert: %s" "$FILE" ' Before this change, the regular write stops at the 3 MiB limit, but insert range grows the file to 4 MiB: dd: error writing '/mnt/cifs/repro': File too large size after write: 3145728 size after insert: 4194304 After this change, insert range also fails at the limit and leaves the 2 MiB file unchanged: dd: error writing '/mnt/cifs/repro': File too large size after write: 3145728 fallocate: fallocate failed: File too large size after insert: 2097152

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Sep 25, 2026
Updated
Oct 22, 2026
EPSS
0.1% · 2th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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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.

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 kernel5.13 and later · before 6.6.160
  • linux linux kernel6.7 and later · before 6.12.111
  • linux linux kernel6.13 and later · before 6.18.53
  • linux linux kernel6.19 and later · before 7.2.7
  • linux linux kernel7.3

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

    • 5.13affected
    • 7fe6fe95b936084dce6eedcc2cccadf96eafae73 and later · before b7f2e33d9f5db7b8e6e5e0a5a93d0c5e31870356affected · git
    • 7fe6fe95b936084dce6eedcc2cccadf96eafae73 and later · before 7c2c69045aa76ccaa7f16f1478eb312130ce4951affected · git
    • 7fe6fe95b936084dce6eedcc2cccadf96eafae73 and later · before bc7602b9082ef195d913c4c16fa9853dd262333eaffected · git
    • 7fe6fe95b936084dce6eedcc2cccadf96eafae73 and later · before f8cbfe3a3fcee7d991fd223f660f3e5df13221cfaffected · git
    • 7fe6fe95b936084dce6eedcc2cccadf96eafae73 and later · before 1519dc88c87f5346dae0464d7d6da1b6bf1f6e8eaffected · git
    • before 5.13not affected · semver
    • 6.6.160 and later · up to and including 6.6.*not affected · semver
    • 6.12.111 and later · up to and including 6.12.*not affected · semver
    • 6.18.53 and later · up to and including 6.18.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.7-17.2.7-1

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-2026-98125Sep 25, 2026 · smb/client: fix stale page cache in insert/collapse range
    22Monitor
  • ← EarlierCVE-2026-98126Sep 25, 2026 · smb/client: validate new EOF for zero range
    22Monitor
  • Later →CVE-2026-98128Sep 25, 2026 · scsi: mpi3mr: Fix target device refcount leak in mpi3mr_sas_port_add()
    22Monitor

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 Linux1519dc88c87f5346dae0464d7d6da1b6bf1f6e8eVendor (CNA)
Linux Linux7c2c69045aa76ccaa7f16f1478eb312130ce4951Vendor (CNA)
Linux Linuxb7f2e33d9f5db7b8e6e5e0a5a93d0c5e31870356Vendor (CNA)
Linux Linuxbc7602b9082ef195d913c4c16fa9853dd262333eVendor (CNA)
Linux Linuxf8cbfe3a3fcee7d991fd223f660f3e5df13221cfVendor (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)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

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.

  • CVE-2026-46325108 days apartRDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE
    39Monitor
  • CVE-2026-46039121 days apartrxgk: Fix potential integer overflow in length check
    39Monitor
  • CVE-2026-43341140 days apartnet/ipv6: ioam6: prevent schema length wraparound in trace fill
    39Monitor
  • CVE-2026-31633154 days apartrxrpc: Fix integer overflow in rxgk_verify_response()
    39Monitor
  • CVE-2026-31649154 days apartnet: stmmac: fix integer underflow in chain mode
    39Monitor
  • CVE-2026-31659154 days apartbatman-adv: reject oversized global TT response buffers
    39Monitor

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
none
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
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-190 · Integer Overflow or Wraparound

CVSS vector

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

nvd-primary

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. CVSS— → 5.5
  2. Severity— → medium
  3. Fix✗ → ✓

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

References

Show all references (4 more)

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

All records