9.8

CVE-2025-39702: ipv6: sr: Fix MAC comparison to be constant-time

Modified
AliasesUBUNTU-CVE-2025-39702DEBIAN-CVE-2025-39702
Published 05-09-2025Last modified 15-10-2026

Vulnerability summary

CVE-2025-39702 is a critical (CVSS 9.8) Observable Discrepancy vulnerability in debian debian_linux. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 37.4% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.8 (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
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.43%
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 56 · Related 41
DLA-4328-1DLA-4475-1DSA-6008-1DSA-6009-1MGASA-2025-0234MGASA-2025-0235

Timeline

  1. 05-09-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: Fix MAC comparison to be constant-time To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.43%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.43% 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.

Ubuntu147 products
  • linuxAll versions (No fix recorded) | < 5.15.0-163.173 | < 6.8.0-100.100
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1097.104 | < 6.8.0-1046.49
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linux< 6.1.153-1 | < 6.12.48-1 | < 6.16.5-1
  • debian_linuxEOL11.0
Linux2 products
  • linux≥ bf355b8d2c30a289232042cacc1cfaea4923936c, < ff55a452d56490047f5233cc48c5d933f8586884 | ≥ bf355b8d2c30a289232042cacc1cfaea4923936c, < 3b348c9c8d2ca2c67559ffd0e258ae7e1107d4f0 | ≥ bf355b8d2c30a289232042cacc1cfaea4923936c, < 86b6d34717fe0570afce07ee79b8eeb40341f831 | ≥ bf355b8d2c30a289232042cacc1cfaea4923936c, < 3ddd55cf19ed6cc62def5e3af10c2a9df1b861c3 | ≥ bf355b8d2c30a289232042cacc1cfaea4923936c, < b3967c493799e63f648e9c7b6cb063aa2aed04e7 | ≥ bf355b8d2c30a289232042cacc1cfaea4923936c, < f7878d47560d61e3f370aca3cebb8f42a55b990a | ≥ bf355b8d2c30a289232042cacc1cfaea4923936c, < a458b2902115b26a25d67393b12ddd57d1216aaa | 4.10
  • linux_kernel≥ 4.10, < 5.15.190 | ≥ 5.16, < 6.1.149 | ≥ 6.2, < 6.6.103 | ≥ 6.7, < 6.12.44 | ≥ 6.13, < 6.16.4 | 6.17:rc1 | 6.17:rc2

3 vendors · 151 products

References

39 links
Show all 39 references