5.5

CVE-2025-39899: linux

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2025-39899DEBIAN-CVE-2025-39899
Published 01-10-2025Last modified 11-05-2026
Open JSON

Vulnerability summary

CVE-2025-39899 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 3.2% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.14%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 15 · Related 15
OPENSUSE-SU-2025:20081-1SUSE-SU-2025:21074-1SUSE-SU-2025:21139-1SUSE-SU-2025:21179-1SUSE-SU-2026:20560-1USN-8095-1

Timeline

  1. 01-10-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: mm/userfaultfd: fix kmap_local LIFO ordering for CONFIG_HIGHPTE With CONFIG_HIGHPTE on 32-bit ARM, move_pages_pte() maps PTE pages using kmap_local_page(), which requires unmapping in Last-In-First-Out order. The current code maps dst_pte first, then src_pte, but unmaps them in the same order (dst_pte, src_pte), violating the LIFO requirement. This causes the warning in kunmap_local_indexed(): WARNING: CPU: 0 PID: 604 at mm/highmem.c:622 kunmap_local_indexed+0x178/0x17c addr \!= __fix_to_virt(FIX_KMAP_BEGIN + idx) Fix this by reversing the unmap order to respect LIFO ordering. This issue follows the same pattern as similar fixes: - commit eca6828403b8 ("crypto: skcipher - fix mismatch between mapping and unmapping order") - commit 8cf57c6df818 ("nilfs2: eliminate staggered calls to kunmap in nilfs_rename") Both of which addressed the same fundamental requirement that kmap_local operations must follow LIFO ordering.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.14%

Chance of exploitation in the next 30 days

Percentile

3%

Versus all other CVEs

30-day change

0.00 pp

From 0.14% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.14%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu122 products
  • linux< 6.8.0-106.106
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.8.0-1050.53
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ adef440691bab824e39c1b17382322d195e1fab0, < b051f707018967ea8f697d790a1ed8c443f63812 | ≥ adef440691bab824e39c1b17382322d195e1fab0, < bd1ee62759d0bd4d6b909731c076c230ac89d61e | ≥ adef440691bab824e39c1b17382322d195e1fab0, < 9614d8bee66387501f48718fa306e17f2aa3f2f3 | 6.8
  • linux_kernel≥ 6.8, < 6.12.46 | ≥ 6.13, < 6.16.6 | 6.17:rc1 | 6.17:rc2 | 6.17:rc3 | 6.17:rc4
Debian1 product
  • linux< 6.12.48-1 | < 6.16.6-1

3 vendors · 125 products

References

17 links
Show all 17 references