Critical

CVE-2026-98323 — RDMA/siw: Bound fragmented header copies by the remaining length

In the Linux kernel, the following vulnerability has been resolved: RDMA/siw: Bound fragmented header copies by the remaining length siw_get_hdr() can receive an extended DDP/RDMAP header across more than one TCP callback. The first callback may receive most of the header, while the next one still limits the copy to hdrlen - MIN_DDP_HDR instead of the number of missing bytes. This makes the destination move past the end of the header and overwrite the receive state, including fpdu_part_rcvd. A later callback can then use a negative fpdu_part_rcvd value as a copy offset, which creates an OOB write. Use the number of header bytes already received when calculating the next copy length.

Published Oct 6, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.6% (30-day exploitation probability)+7
Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.56%

ahead of 45% of scored CVEs · Oct 14, 2026

Affects

Linux

CVSS base

9.8

Critical · 2 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	version e09caa38e10bcf027100cc22b0e3cc745a39ef0aversion 6.1≥ 6.0.3 and < 6.1≥ 5.19.17 and < 5.20≥ 5.4.220 and < 5.5≥ 5.15.75 and < 5.15.222≥ 5.10.150 and < 5.10.271version 7fada7c6962219b6fc4ff4e62e46a936af110dd9 and 9 more version 0c14f795a9eab9344230f9933798b8ee496f497d≥ e3917c85f41ef1df64e27dc0e46ab0d803c5e73e and < 2c6fbcf4bfac0b2b186acc8d91154c0fa24468a7≥ 754209850df8367c954ac1de7671c7430b1f342c and < 9ff797e516dbc1ecb73701ec4c24055712d44411≥ 754209850df8367c954ac1de7671c7430b1f342c and < e6bdfdf3bcb02d0d626a45e8c98b7e63d2fddf9d≥ 754209850df8367c954ac1de7671c7430b1f342c and < b72dcfb9bf1f0f0147cda03dc59e4002a315067f≥ 754209850df8367c954ac1de7671c7430b1f342c and < 8628f8ebf41669302513fb3f0bf0eba38b226742≥ 754209850df8367c954ac1de7671c7430b1f342c and < eb4d7a946970469b3ab0c762432bf161d5b0836c≥ 754209850df8367c954ac1de7671c7430b1f342c and < 262dcd809723723ed8a4e05437ec7e9c21a8f17e≥ 308cd50f174c95a507527037f4de1a0396aa4325 and < af9f5b474a260ad23ffb9793d716a5e3bbce3b48	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.8	CVSS 3.1	Critical	3.9	5.9	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
9.8	CVSS 3.1	Critical	—	—	Linux via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.56%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · linux/linux
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
CVSS changed · 9.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Received
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Oct 6, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

8 on the record

git.kernel.org/stable/c/2c6fbcf4bfac0b2b186acc8d91154c0fa24468a7
NIST National Vulnerability Database
git.kernel.org/stable/c/b72dcfb9bf1f0f0147cda03dc59e4002a315067f
NIST National Vulnerability Database
git.kernel.org/stable/c/eb4d7a946970469b3ab0c762432bf161d5b0836c
NIST National Vulnerability Database
git.kernel.org/stable/c/e6bdfdf3bcb02d0d626a45e8c98b7e63d2fddf9d
NIST National Vulnerability Database
git.kernel.org/stable/c/262dcd809723723ed8a4e05437ec7e9c21a8f17e
NIST National Vulnerability Database
git.kernel.org/stable/c/8628f8ebf41669302513fb3f0bf0eba38b226742
NIST National Vulnerability Database
git.kernel.org/stable/c/af9f5b474a260ad23ffb9793d716a5e3bbce3b48
NIST National Vulnerability Database
git.kernel.org/stable/c/9ff797e516dbc1ecb73701ec4c24055712d44411
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 8h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 8h
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-98323 is "RDMA/siw: Bound fragmented header copies by the remaining length", rated Critical. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.8 describes technical severity. EPSS 0.56% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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