9.8

CVE-2026-68123: linux Integer Underflow (Wrap or Wraparound)

CVSS: 9.8v3.1CriticalReceived
AliasesUBUNTU-CVE-2026-68123DEBIAN-CVE-2026-68123
Published 10-08-2026Last modified 19-10-2026
Open JSON

Vulnerability summary

CVE-2026-68123 is a critical (CVSS 9.8) Integer Underflow (Wrap or Wraparound) vulnerability in linux. EPSS estimates a 0.55% chance of exploitation in the next 30 days, higher than 45% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.55%
0%100%
Low · -0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 31 · Related 27
MGASA-2026-0336MGASA-2026-0337OPENSUSE-SU-2026:21910-1RHSA-2026:81406RHSA-2026:81552SUSE-SU-2026:23477-1

Timeline

  1. 10-08-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: openvswitch: fix GSO userspace truncation underflow OVS_ACTION_ATTR_TRUNC currently stores a delta from the original skb length in OVS_CB(skb)->cutlen. When a later userspace action segments a GSO skb, queue_gso_packets() reuses that delta for each smaller segment. A segment can then reach queue_userspace_packet() with cutlen greater than skb->len, underflowing the length passed to skb_zerocopy(). Store the maximum preserved length instead and bound each consumer against the current skb length. Use U32_MAX as the no-truncation sentinel so the value remains valid if skb geometry changes before a consumer handles it.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.55%

Chance of exploitation in the next 30 days

Percentile

45%

Versus all other CVEs

30-day change

-0.01 pp

From 0.56% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.55%

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

Affected systems

Ubuntu168 products
  • linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-147.147 | < 7.0.0-38.38
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1067.70 | < 7.0.0-1014.14
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linux< 6.1.187-1 | < 6.12.101-1 | < 7.1.6-1
  • linux-6.12< 6.12.101-1~deb12u1
Linux1 product
  • linux≥ f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1, < 50a6a85f3d6b1d22d8436848606cdef5d2c490b4 | ≥ f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1, < 2623c48cc3a8da9a1886fd8f65c0e348f4406fd6 | ≥ f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1, < e211b081901ffca76674082c73eeaed53524c369 | ≥ f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1, < a16eaaf7c0b0ccdef6166707d90ffbc6eebf6855 | ≥ f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1, < fbfa3ad2ad6f3a5624aba5211c46290fb98cc9dc | ≥ f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1, < 100a23b1613e9218e0af654ef102352c713f0263 | ≥ f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1, < ea85dbcbe8d4056ecb54352f97743d138ea4c407 | ≥ f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1, < 4032f8ed10fcb84d41c508dfb04be96589f78dfe | 4.8

3 vendors · 171 products

References

27 links
Show all 27 references