CVE-2026-90088
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().
Affected versions
Linux kernel versions
2.6.12
and later are affected. Fixed in
5.10.270,
5.15.221,
6.1.188,
6.6.157,
6.12.110,
6.18.52,
7.2.6,
7.3-rc1
and their respective stable series.
References
8 totalFrequently asked questions
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What is CVE-2026-90088?
CVE-2026-90088 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 2.6.12 onward and has been patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-90088 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-90088?
Yes. CVE-2026-90088 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-90088 actively exploited?
No. CVE-2026-90088 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.