CVE-2026-98621: net: gue: reject invalid REMCSUM offsets
Noroxi assessment
Priority: Monitor (action score 0/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.21% (FIRST EPSS).
- Fixed version: Linux Linux 1d664be4ca49d1696e85239236f4988dfc4653c3, 1eeec0c51fd5598da44080ed96bbd9880021c28b, 2566866fc30965d915d0b52b5c3323b362619f0e; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to Linux Linux 1d664be4ca49d1696e85239236f4988dfc4653c3, 1eeec0c51fd5598da44080ed96bbd9880021c28b, 2566866fc30965d915d0b52b5c3323b362619f0e; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.159.1-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Oct 18, 2026
- Updated
- Oct 19, 2026
- EPSS
- 0.2% · 12th percentile
- CWE
- —
Report tools
Action score
0
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 4.0affected
- fe881ef11cf0220f118816181930494d484c4883 and later · before 4b9bc21b2396c396d88dd909caaf73d5be6ff593affected · git
- fe881ef11cf0220f118816181930494d484c4883 and later · before 43efb1f997e976f386aa89716f55870cd2cff9adaffected · git
- fe881ef11cf0220f118816181930494d484c4883 and later · before 1eeec0c51fd5598da44080ed96bbd9880021c28baffected · git
- fe881ef11cf0220f118816181930494d484c4883 and later · before 1d664be4ca49d1696e85239236f4988dfc4653c3affected · git
- fe881ef11cf0220f118816181930494d484c4883 and later · before 97f907203321eee2cc9132d5c9eb47698fb41d35affected · git
- fe881ef11cf0220f118816181930494d484c4883 and later · before 40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57faffected · git
- fe881ef11cf0220f118816181930494d484c4883 and later · before c20f755338ca234e523dfc943719f194dfc1f903affected · git
- fe881ef11cf0220f118816181930494d484c4883 and later · before 2566866fc30965d915d0b52b5c3323b362619f0eaffected · git
- before 4.0not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.190-1 | 6.1.190-1 |
| Debian:12 | linux-6.12 | before 6.12.113-1~deb12u1 | 6.12.113-1~deb12u1 |
| Debian:13 | linux | before 6.12.113-1 | 6.12.113-1 |
| Debian:14 | linux | before 7.2.9-1 | 7.2.9-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2026-98619Oct 18, 2026 · net: ethtool: keep rtnl_lock for the ioctl self test0Monitor
- ← EarlierCVE-2026-98620Oct 18, 2026 · net: ethernet: mtk_eth_soc: unregister net_devices in case of probe failure0Monitor
- Later →CVE-2026-98622Oct 18, 2026 · net/sched: act_ct: don't WARN on benign flow_offload_alloc() failure0Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 1d664be4ca49d1696e85239236f4988dfc4653c3 | Vendor (CNA) |
| Linux Linux | 1eeec0c51fd5598da44080ed96bbd9880021c28b | Vendor (CNA) |
| Linux Linux | 2566866fc30965d915d0b52b5c3323b362619f0e | Vendor (CNA) |
| Linux Linux | 40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f | Vendor (CNA) |
| Linux Linux | 43efb1f997e976f386aa89716f55870cd2cff9ad | Vendor (CNA) |
| Linux Linux | 4b9bc21b2396c396d88dd909caaf73d5be6ff593 | Vendor (CNA) |
| Linux Linux | 97f907203321eee2cc9132d5c9eb47698fb41d35 | Vendor (CNA) |
| Linux Linux | c20f755338ca234e523dfc943719f194dfc1f903 | Vendor (CNA) |
| azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 | 6.6.159.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.1.190-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.113-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
- Published
- Fix recordedsame day
- TodayNov 13, 2026+26 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-1351 · Oct 19, 2026(Linux Kernel Güvenlik Bildirimi)
Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log (2)
- Exploit maturity— → none
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (7 more)Show less
- git.kernel.org/stable/c/1eeec0c51fd5598da44080ed96bbd9880021c28b
- git.kernel.org/stable/c/2566866fc30965d915d0b52b5c3323b362619f0e
- git.kernel.org/stable/c/40aeafbcbc7bc4018e8f74bbbb4d29ed8846f57f
- git.kernel.org/stable/c/43efb1f997e976f386aa89716f55870cd2cff9ad
- git.kernel.org/stable/c/4b9bc21b2396c396d88dd909caaf73d5be6ff593
- git.kernel.org/stable/c/97f907203321eee2cc9132d5c9eb47698fb41d35
- git.kernel.org/stable/c/c20f755338ca234e523dfc943719f194dfc1f903
Vendor advisories and official records. Exploit/PoC links are deliberately left out.