6.8

CVE-2026-80847: linux

CVSS: 6.8v4.0MediumReceived
AliasesUBUNTU-CVE-2026-80847DEBIAN-CVE-2026-80847
Published 04-09-2026Last modified 21-10-2026
Open JSON

Vulnerability summary

CVE-2026-80847 is a medium (CVSS 6.8) vulnerability in linux. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 5.7% of scored vulnerabilities.

Overall risk
27/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.8/10
010
Medium · v4.0 (OSV · Ubuntu), selected by version preference
EPSS score
0.17%
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 11 · Related 11
OPENSUSE-SU-2026:11773-1OPENSUSE-SU-2026:22091-1SUSE-SU-2026:24179-1SUSE-SU-2026:24181-1SUSE-SU-2026:24182-1SUSE-SU-2026:24184-1

Timeline

  1. 04-09-2026
    PublishedVulnerability first disclosed.
  2. 21-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: tcp: clamp route advmss to TCP_MIN_MSS tcp_select_initial_window() assumes that callers never pass an MSS smaller than 1, but route-derived advmss values can violate that assumption. A too-small explicit RTAX_ADVMSS is one way to get there, but it is not the only one. The same divide-by-zero can also be reached through the "default advmss" path when RTAX_ADVMSS is left at 0 and the effective advmss is later driven down by route MTU and min_adv_mss. Introduce a tcp_dst_advmss() helper that clamps route advmss to TCP_MIN_MSS before TCP consumes it, and use it in the TCP paths that derive advmss from dst metrics. This keeps the effective MSS from dropping to zero before tcp_select_initial_window() rounds the receive window.

CVSS metrics

1 score · 1 source · 1 version

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

6%

Versus all other CVEs

30-day change

0.00 pp

From 0.17% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.17%

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

Ubuntu169 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 | < 7.1.13-1
  • linux-6.12< 6.12.111-1~deb12u1
Linux1 product
  • linux≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 788fbbf7d61f9742298417c207c91b6db159fbbc | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < eaf4af9bd6975c2eff8d48820937c83032d968dc | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < cfb44c6028e6f979720315e0772bbd0d4d33ed61 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 6b8c20bf61924dfc38fefb145c9f7406d73fae53 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 31cf2349361902769dc323e4dbf4b449795ec288 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 870a9e42ecc6fe1b8c25d87af043cb0d9c178fe1 | 2.6.12

3 vendors · 172 products

References

10 links