5.5

CVE-2026-98126: smb/client: validate new EOF for zero range

Analyzed
AliasesUBUNTU-CVE-2026-98126DEBIAN-CVE-2026-98126
Published 25-09-2026Last modified 21-10-2026

Vulnerability summary

CVE-2026-98126 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 2% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.12%
0%100%
Low · -0.05 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 8 · Related 6
MGASA-2026-0506MGASA-2026-0542OPENSUSE-SU-2026:12074-1OPENSUSE-SU-2026:22167-1SUSE-SU-2026:24386-1SUSE-SU-2026:24422-1

Timeline

  1. 25-09-2026
    PublishedVulnerability first disclosed.
  2. 21-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: smb/client: validate new EOF for zero range When FALLOC_FL_ZERO_RANGE is used without FALLOC_FL_KEEP_SIZE, smb3_zero_range() may extend EOF without checking RLIMIT_FSIZE, allowing the file to grow beyond the caller's file-size limit. Fix this by calling inode_newsize_ok() before sending the zero-range request when the operation would extend EOF. Reproducer, using a file on a CIFS mount: bash -c ' FILE=/mnt/cifs/repro trap "" SIGXFSZ ulimit -f 3072 truncate -s 2M "$FILE" fallocate --zero-range -o 0 -l 4M "$FILE" echo "fallocate rc=$?" stat -c "file size=%s" "$FILE" ' Before this change, the operation succeeds despite the 3 MiB limit: fallocate rc=0 file size=4194304 After this change, fallocate fails and leaves the file at 2 MiB.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.12%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

Decrease -0.05 pp

From 0.17% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu165 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linuxAll versions (No fix recorded) | < 6.12.111-1 | < 7.2.7-1
  • linux-6.12< 6.12.111-1~deb12u1
Linux2 products
  • linux≥ 72c419d9b073628d3b5b0b2fc787b724f1a8c726, < 5fbd8848f2e25c8163896ec52863df2305a3bb63 | ≥ 72c419d9b073628d3b5b0b2fc787b724f1a8c726, < 3673f057b64abfa957e8ae84448db69369a5091a | ≥ 72c419d9b073628d3b5b0b2fc787b724f1a8c726, < 06a4f9049cb6dc319bceec2dc813ba89add8b828 | ≥ 72c419d9b073628d3b5b0b2fc787b724f1a8c726, < f320ca20c273a26cd779bdb2b2e4b076a95c76f6 | ≥ 72c419d9b073628d3b5b0b2fc787b724f1a8c726, < 88972e35750792e717af287dc71f42a03b5cbce4 | 5.1
  • linux_kernel≥ 5.1, < 6.6.160 | ≥ 6.7, < 6.12.111 | ≥ 6.13, < 6.18.53 | ≥ 6.19, < 7.2.7 | 7.3:rc1

3 vendors · 169 products

References

8 links