---
cve: "CVE-2026-90088"
severity: "LOW"
cvss: 3.1
epss: "5.3%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-17 17:16:59"
tags: [cve, security, low]
source: tsecurity.de CVE-Dossier
exported: "2026-09-22T01:15:31+02:00"
---

# CVE-2026-90088

> 3.1 LOW

## Beschreibung

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: RFCOMM: Validate MTU in rfcomm_apply_pn() to prevent infinite loop

rfcomm_apply_pn() accepts the MTU value from a remote PN (Parameter
Negotiation) frame without checking for zero. When the remote peer
sends an MTU of zero, d->mtu is set to 0. This causes the sendmsg
path to enter an infinite loop when fragmenting data, as each fragment
has size == min_t(size_t, len, 0) == 0, so the remaining length never
decreases. The infinite allocation of zero-length skbs exhausts all
system memory.

Fix by clamping d->mtu to RFCOMM_DEFAULT_MTU when the negotiated
value is zero, consistent with the initial value assigned in
rfcomm_dlc_alloc().

## Patch verfügbar (OSV)

- Kernel ≥ 5.10.270
- Kernel ≥ 5.15.221
- Kernel ≥ 6.1.188
- Kernel ≥ 6.6.157
- Kernel ≥ 6.12.110
- Kernel ≥ 6.18.52
- Kernel ≥ 7.2.6

## Referenzen

- <https://git.kernel.org/stable/c/3988cbb1be501dbff909a2ee024670e3c955a66d>
- <https://git.kernel.org/stable/c/44c98fd082eafd49d55a8a4077ff488175b2fe24>
- <https://git.kernel.org/stable/c/9b2e5f1928c99224345a9ed8c5dae5fc74964d6d>
- <https://git.kernel.org/stable/c/aeee917a4878af95f0c63e18c5f22eaf6299c7b8>
- <https://git.kernel.org/stable/c/cbc2962da99b6b89345267d3aa74b4b573340548>
- <https://git.kernel.org/stable/c/e7c0aa45ae6c5a338661b23812bfcdef50bf3e96>
- <https://git.kernel.org/stable/c/f561e44261344adadf9d6a6dff31e3af9776d5c6>
- <https://git.kernel.org/stable/c/fc4851ff8dfb505e9a19efcc286712132bbd178d>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-90088) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_