7.5

CVE-2025-21844: smb: client: Add check for next_buffer in receive_encrypted_standard()

Modified
AliasesUBUNTU-CVE-2025-21844DEBIAN-CVE-2025-21844
Published 12-03-2025Last modified 15-10-2026

Vulnerability summary

CVE-2025-21844 is a high (CVSS 7.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.62% chance of exploitation in the next 30 days, higher than 49.7% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.62%
0%100%
Low · +0.01 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 39 · Related 33
DLA-4178-1DLA-4193-1DSA-5900-1MGASA-2025-0111MGASA-2025-0112RHSA-2025:20095

Timeline

  1. 12-03-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: Add check for next_buffer in receive_encrypted_standard() Add check for the return value of cifs_buf_get() and cifs_small_buf_get() in receive_encrypted_standard() to prevent null pointer dereference.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.62%

Chance of exploitation in the next 30 days

Percentile

50%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.61% 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: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu133 products
  • linuxAll versions (No fix recorded) | < 5.15.0-140.150 | < 6.8.0-78.78
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1084.91 | < 6.8.0-1035.37
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ b03c8099a738a04d2343547ae6a04e5f0f63d3fa, < f277e479eea3d1aa18bc712abe1d2bf3dece2e30 | ≥ 858e73ff25639a0cc1f6f8d2587b62c045867e41, < f618aeb6cad2307e48a641379db610abcf593edf | ≥ 9f528a8e68327117837b5e28b096f52af4c26a05, < 24e8e4523d3071bc5143b0db9127d511489f7b3b | ≥ 534733397da26de0303057ce0b93a22bda150365, < 9e5d99a4cf2e23c716b44862975548415fae5391 | ≥ eec04ea119691e65227a97ce53c0da6b9b74b0b7, < a9b0b4b29877cb4dc5d0842b59b5ccbacddb85bd | ≥ eec04ea119691e65227a97ce53c0da6b9b74b0b7, < 554736b583f529ee159aa95af9a0cbc12b5ffc96 | ≥ eec04ea119691e65227a97ce53c0da6b9b74b0b7, < 860ca5e50f73c2a1cef7eefc9d39d04e275417f7 | ≥ 5.10.211, < 5.10.235 | ≥ 5.15.150, < 5.15.179 | ≥ 6.1.69, < 6.1.130 | ≥ 6.6.8, < 6.6.80 | 6.7
  • linux_kernel≥ 6.1.69, < 6.1.130 | ≥ 6.6.8, < 6.6.80 | ≥ 6.7, < 6.12.17 | ≥ 6.13, < 6.13.5 | 5.10.211 | 5.15.150 | 6.14:rc1 | 6.14:rc2 | 6.14:rc3
Debian1 product
  • linux< 6.1.133-1 | < 6.12.17-1

3 vendors · 136 products

References

39 links
Show all 39 references