CVE-2026-68300: linux Improper Authentication
Vulnerability summary
CVE-2026-68300 is a critical (CVSS 9.8) Improper Authentication vulnerability in linux. EPSS estimates a 0.58% chance of exploitation in the next 30 days, higher than 46.7% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 33 · Related 27Timeline
- 10-08-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVDNIST9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.58%
Chance of exploitation in the next 30 days
Percentile
47%
Versus all other CVEs
30-day change
-0.02 pp
From 0.60% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu169 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≥ bbd0d59809f923ea2b540cbd781b32110e249f6e, < a129792b3aef15002746c13522781d92ed3522c3 | ≥ bbd0d59809f923ea2b540cbd781b32110e249f6e, < 5a022ac51ad83b4ce6c898f4b9eefc65bd26b247 | ≥ bbd0d59809f923ea2b540cbd781b32110e249f6e, < 6caf0e8590c0bf05a76b0d387726adf3a6f3725c | ≥ bbd0d59809f923ea2b540cbd781b32110e249f6e, < ec2e157fc9678a9bc411305a25aec3fd337d7efb | ≥ bbd0d59809f923ea2b540cbd781b32110e249f6e, < 28c5fdce9dd955d2baf5e28987819b6d7cfaf646 | ≥ bbd0d59809f923ea2b540cbd781b32110e249f6e, < 18957373920caf5cdaf5cf32e5d1d7a99ca7700a | ≥ bbd0d59809f923ea2b540cbd781b32110e249f6e, < 83f5031f2a6a49d696eb4cc0898345d12f9c6451 | ≥ bbd0d59809f923ea2b540cbd781b32110e249f6e, < 8e04823c120b376ef7dab14b60ebf6823aa16c14 | 2.6.24
3 vendors · 172 products
