Critical

CVE-2026-68300 — sctp: auth: verify auth requirement when auth_chunk is NULL

In the Linux kernel, the following vulnerability has been resolved: sctp: auth: verify auth requirement when auth_chunk is NULL sctp_auth_chunk_verify() returns true unconditionally when chunk->auth_chunk is NULL, silently skipping authentication. This is incorrect when: 1. skb_clone() failed in the BH receive path, leaving auth_chunk NULL. In sctp_endpoint_bh_rcv() asoc is NULL for new connections, so the early sctp_auth_recv_cid() check cannot catch this. 2. No AUTH chunk precedes COOKIE-ECHO, so skb_clone() is never called and auth_chunk remains NULL. Fix by checking sctp_auth_recv_cid() when auth_chunk is NULL: if authentication is required, return false to drop the chunk; otherwise continue normally.

Published Aug 10, 2026 · Updated Oct 15, 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

0.59%

ahead of 47% of scored CVEs · Oct 15, 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	≥ bbd0d59809f923ea2b540cbd781b32110e249f6e and < a129792b3aef15002746c13522781d92ed3522c3≥ bbd0d59809f923ea2b540cbd781b32110e249f6e and < 5a022ac51ad83b4ce6c898f4b9eefc65bd26b247≥ bbd0d59809f923ea2b540cbd781b32110e249f6e and < 6caf0e8590c0bf05a76b0d387726adf3a6f3725c≥ bbd0d59809f923ea2b540cbd781b32110e249f6e and < ec2e157fc9678a9bc411305a25aec3fd337d7efb≥ bbd0d59809f923ea2b540cbd781b32110e249f6e and < 28c5fdce9dd955d2baf5e28987819b6d7cfaf646≥ bbd0d59809f923ea2b540cbd781b32110e249f6e and < 18957373920caf5cdaf5cf32e5d1d7a99ca7700a≥ bbd0d59809f923ea2b540cbd781b32110e249f6e and < 83f5031f2a6a49d696eb4cc0898345d12f9c6451≥ bbd0d59809f923ea2b540cbd781b32110e249f6e and < 8e04823c120b376ef7dab14b60ebf6823aa16c14 and 1 more version 2.6.24	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)

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 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 9.8
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Aug 10, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

8 on the record

git.kernel.org/stable/c/ec2e157fc9678a9bc411305a25aec3fd337d7efb
NIST National Vulnerability Database
git.kernel.org/stable/c/5a022ac51ad83b4ce6c898f4b9eefc65bd26b247
NIST National Vulnerability Database
git.kernel.org/stable/c/8e04823c120b376ef7dab14b60ebf6823aa16c14
NIST National Vulnerability Database
git.kernel.org/stable/c/28c5fdce9dd955d2baf5e28987819b6d7cfaf646
NIST National Vulnerability Database
git.kernel.org/stable/c/6caf0e8590c0bf05a76b0d387726adf3a6f3725c
NIST National Vulnerability Database
git.kernel.org/stable/c/a129792b3aef15002746c13522781d92ed3522c3
NIST National Vulnerability Database
git.kernel.org/stable/c/18957373920caf5cdaf5cf32e5d1d7a99ca7700a
NIST National Vulnerability Database
git.kernel.org/stable/c/83f5031f2a6a49d696eb4cc0898345d12f9c6451
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 22h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 22h
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 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-2026-68300 is "sctp: auth: verify auth requirement when auth_chunk is NULL", 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 0.59% 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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