9.4

CVE-2025-40099: cifs: parse_dfs_referrals: prevent oob on malformed input

Deferred
AliasesUBUNTU-CVE-2025-40099DEBIAN-CVE-2025-40099
Published 30-10-2025Last modified 15-10-2026

Vulnerability summary

CVE-2025-40099 is a critical (CVSS 9.4) vulnerability in linux. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 34.9% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.4 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.4/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.41%
0%100%
Low · 0.00 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 33 · Related 29
DLA-4379-1DSA-6053-1MGASA-2025-0309MGASA-2025-0310OPENSUSE-SU-2025:15702-1OPENSUSE-SU-2026:10301-1

Timeline

  1. 30-10-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: cifs: parse_dfs_referrals: prevent oob on malformed input Malicious SMB server can send invalid reply to FSCTL_DFS_GET_REFERRALS - reply smaller than sizeof(struct get_dfs_referral_rsp) - reply with number of referrals smaller than NumberOfReferrals in the header Processing of such replies will cause oob. Return -EINVAL error on such replies to prevent oob-s.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.41%

Chance of exploitation in the next 30 days

Percentile

35%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.41% 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

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu153 products
  • linuxAll versions (No fix recorded) | < 6.8.0-106.106 | < 6.17.0-14.14
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1050.53 | < 6.17.0-1007.7
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.1.158-1 | < 6.12.57-1 | < 6.17.6-1
Linux1 product
  • linux≥ 4ecce920e13ace16a5ba45efe8909946c28fb2ad, < cfacc7441f760e4a73cc71b6ff1635261d534657 | ≥ 4ecce920e13ace16a5ba45efe8909946c28fb2ad, < 15c73964da9df994302f579ed14ee5fdbce7a332 | ≥ 4ecce920e13ace16a5ba45efe8909946c28fb2ad, < 8bc4a8d39bac23d8b044fd3e2dbfd965f1d9b058 | ≥ 4ecce920e13ace16a5ba45efe8909946c28fb2ad, < bb0f2e66e1ac043a5b238f5bcab4f26f3c317039 | ≥ 4ecce920e13ace16a5ba45efe8909946c28fb2ad, < 6447b0e355562a1ff748c4a2ffb89aae7e84d2c9 | 4.11

3 vendors · 155 products

References

25 links
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