8.6

CVE-2026-46273: ibmveth: Disable GSO for packets with small MSS

Modified
AliasesUBUNTU-CVE-2026-46273DEBIAN-CVE-2026-46273
Published 03-06-2026Last modified 07-08-2026

Vulnerability summary

CVE-2026-46273 is a high (CVSS 8.6) Uncontrolled Resource Consumption vulnerability in linux. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 33% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 8.6 (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
8.6/10
010
High · v3.1 (CVE.org)
EPSS score
0.39%
0%100%
Low · -0.33 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 55 · Related 55
OPENSUSE-SU-2026:11014-1OPENSUSE-SU-2026:21555-1SUSE-SU-2026:22433-1SUSE-SU-2026:22436-1SUSE-SU-2026:22458-1SUSE-SU-2026:22460-1

Timeline

  1. 03-06-2026
    PublishedVulnerability first disclosed.
  2. 07-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ibmveth: Disable GSO for packets with small MSS Some physical adapters on Power systems do not support segmentation offload when the MSS is less than 224 bytes. Attempting to send such packets causes the adapter to freeze, stopping all traffic until manually reset. Implement ndo_features_check to disable GSO for packets with small MSS values. The network stack will perform software segmentation instead. The 224-byte minimum matches ibmvnic commit <f10b09ef687f> ("ibmvnic: Enforce stronger sanity checks on GSO packets") which uses the same physical adapters in SEA configurations. The issue occurs specifically when the hardware attempts to perform segmentation (gso_segs > 1) with a small MSS. Single-segment GSO packets (gso_segs == 1) do not trigger the problematic LSO code path and are transmitted normally without segmentation. Add an ndo_features_check callback to disable GSO when MSS < 224 bytes. Also call vlan_features_check() to ensure proper handling of VLAN packets, particularly QinQ (802.1ad) configurations where the hardware parser may not support certain offload features. Validated using iptables to force small MSS values. Without the fix, the adapter freezes. With the fix, packets are segmented in software and transmission succeeds. Comprehensive regression testing completedd (MSS tests, performance, stability).

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.39%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

Decrease -0.33 pp

From 0.72% 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.

Ubuntu166 products
  • linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136 | < 7.0.0-28.28
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64 | < 7.0.0-1009.9
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 8641dd85799f85bef5f0d1f87356aaa12cb2195e, < 86fc64584811d43c9ccd74447de58620189d8b77 | ≥ 8641dd85799f85bef5f0d1f87356aaa12cb2195e, < 9a5e984d7af910e46dcbed3ce77873e000a4f77d | ≥ 8641dd85799f85bef5f0d1f87356aaa12cb2195e, < 1cdf5dbcec988d06f5f720bdf89e91073f77fa10 | ≥ 8641dd85799f85bef5f0d1f87356aaa12cb2195e, < 82bc89fbb82d9396fb4eaee8720ea85e2e787957 | ≥ 8641dd85799f85bef5f0d1f87356aaa12cb2195e, < db8012c631cb845e9ae2b4b531e17d86c9519755 | ≥ 8641dd85799f85bef5f0d1f87356aaa12cb2195e, < c1f261863e65b508f37416dfbc5c5d911c9b9233 | ≥ 8641dd85799f85bef5f0d1f87356aaa12cb2195e, < 3af24f0c4c31f18a4a2d927990759194832bb6e9 | ≥ 8641dd85799f85bef5f0d1f87356aaa12cb2195e, < cc427d24ac6442ffdeafd157a63c7c5b73ed4de4 | 4.2
  • linux_kernel≥ 4.2, < 5.10.258 | ≥ 5.11, < 5.15.209 | ≥ 5.16, < 6.1.175 | ≥ 6.2, < 6.6.140 | ≥ 6.7, < 6.12.88 | ≥ 6.13, < 6.18.30 | ≥ 6.19, < 7.0.7 | 7.1:rc1
Debian1 product
  • linux< 6.1.176-1 | < 6.12.88-1 | < 7.0.7-1

3 vendors · 169 products

References

51 links
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