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  4. CVE 2026 98621 net gue reject invalid remcsum offsets
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Copyright ยฉ 2026 HOL DAO LLC. All rights reserved.

Back to active CVEs
Unknown severity ยท Source severity not reportedCVE-2026-98621

net: gue: reject invalid REMCSUM offsetsCVE-2026-98621

Answer in brief

CVE-2026-98621 records a Unknown severity vulnerability in net: gue: reject invalid REMCSUM offsets. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 18, 2026Updated Oct 19, 2026Source checked Oct 25, 2026First seen by HOL Oct 18, 2026Material review Oct 19, 2026
Upstream Advisory

Record context

Vulnerability class
Vulnerability
EPSS
Not reported
CWE IDs
Not reported
Source
CVE List V5
Source checked
Oct 25, 2026
References
8 linked sources
Open source record

Key facts

Risk
Unknown severitySource severity not reported
Exploitation
Not marked as known exploited
Affected software
2 mapped packages or products
Fix availability
Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
Linux/Linuxgeneric>=fe881ef11cf0220f118816181930494d484c4883 <4b9bc21b2396c396d88dd909caaf73d5be6ff593 || >=fe881ef11cf0220f118816181930494d484c4883 <43efb1f997e976f386aa89716f55870cd2cff9ad || >=fe881ef11cf0220f118816181930494d484c4883 <1eeec0c51fd5598da44080ed96bbd9880021c28b || >=fe881ef11cf0220f118816181930494d484c4883 <1d664be4ca49d1696e85239236f4988dfc4653c3 || >=fe881ef11cf0220f118816181930494d484c4883 <97f907203321eee2cc9132d5c9eb47698fb41d35 || >=fe881ef11cf0220f118816181930494d484c4883 <40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f || >=fe881ef11cf0220f118816181930494d484c4883 <c20f755338ca234e523dfc943719f194dfc1f903 || >=fe881ef11cf0220f118816181930494d484c4883 <2566866fc30965d915d0b52b5c3323b362619f0e4b9bc21b2396c396d88dd909caaf73d5be6ff593, 43efb1f997e976f386aa89716f55870cd2cff9ad, 1eeec0c51fd5598da44080ed96bbd9880021c28b, 1d664be4ca49d1696e85239236f4988dfc4653c3, 97f907203321eee2cc9132d5c9eb47698fb41d35, 40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f, c20f755338ca234e523dfc943719f194dfc1f903, 2566866fc30965d915d0b52b5c3323b362619f0e
Linux/Linuxgeneric4.0Not reported

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
  2. 2Review the reported fix. Update Linux/Linux to 4b9bc21b2396c396d88dd909caaf73d5be6ff593 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

  1. Published upstream

    Oct 18, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Oct 19, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Oct 18, 2026

Sources and claim methodology

  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
Upstream source description

In the Linux kernel, the following vulnerability has been resolved: net: gue: reject invalid REMCSUM offsets The REMCSUM option carries an absolute checksum start and checksum field offset. gue_remcsum() passes them to skb_remcsum_process(), whose partial path stores offset - start in the u16 skb->csum_offset variable. If offset is less than start, this underflows. A forwarded packet can retain CHECKSUM_PARTIAL and reach a NETIF_F_HW_CSUM driver which trusts the metadata, leading skb_copy_and_csum_dev() to write two bytes about 64 KiB beyond the destination buffer. Reject reversed tuples in validate_gue_flags(), after the existing length validation, so all GUE parsers enforce the ordering in one place.

Quoted source text, attributed separately from HOL analysis.