CVE-2026-72398: linux
Vulnerability summary
CVE-2026-72398 is a critical (CVSS 9.8) vulnerability in linux. EPSS estimates a 0.72% chance of exploitation in the next 30 days, higher than 53.1% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 21 · Related 21Timeline
- 15-08-2026PublishedVulnerability first disclosed.
- 16-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: add INIT verification after cookie unpacking In SCTP handshake, the INIT chunk is initially processed by the server and embedded into the cookie carried in INIT-ACK. The client then returns this cookie via COOKIE-ECHO, where the server unpacks it and reconstructs the original INIT chunk. When cookie authentication is enabled, the cookie contents are protected against tampering, so reusing the unpacked INIT without re-verification is safe. However, when cookie authentication is disabled, the reconstructed INIT can no longer be trusted. In this case, the INIT must be explicitly validated after unpacking to avoid processing potentially tampered data. Add sctp_verify_init() checks after cookie unpacking in COOKIE-ECHO processing paths (sctp_sf_do_5_1D_ce() and sctp_sf_do_5_2_4_dupcook()) when cookie_auth_enable is disabled. On failure, the new association is freed and the packet is discarded. Also tighten cookie validation in sctp_unpack_cookie() by verifying the embedded chunk type is SCTP_CID_INIT before treating it as an INIT chunk. Finally, update sctp_verify_init() to validate parameter bounds using the actual embedded INIT length instead of chunk->chunk_end, since the INIT stored in COOKIE-ECHO may not span the entire chunk buffer.
CVSS metrics
5 scores · 4 sources · 2 versions- 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
0.72%
Chance of exploitation in the next 30 days
Percentile
53%
Versus all other CVEs
30-day change
+0.02 pp
From 0.70% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu169 products
- linuxAll versions (No fix recorded) | < 7.0.0-34.34
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 7.0.0-1013.13
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian1 product
- linuxAll versions (No fix recorded) | < 7.1.5-1
Linux1 product
- linux≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < bca3100f550281c2f2418652338bced3b35af0e6 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 062bcbf8d1f1051fdeb20b94920031b0e2cb95a2 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 414c5447fe6a200613dd46d7fdc8454622076cb1 | 2.6.12
3 vendors · 171 products