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NVD / CVE Program· CNA Linux

CVE-2026-90090: Bluetooth: btmtksdio: Fix out-of-bounds DMA read in the TX path

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.21% (FIRST EPSS).
  • Fixed version: Linux Linux 0b71a6caaf284915c8cf9cd320ecee9f0361824a, 7b37556d7d801b79096c7ba8ea92db2338aa8b00, 7b80d2701a68456c536f82e577dbed2f60ccb82b.

Low priority for now. Upgrade to Linux Linux 0b71a6caaf284915c8cf9cd320ecee9f0361824a, 7b37556d7d801b79096c7ba8ea92db2338aa8b00, 7b80d2701a68456c536f82e577dbed2f60ccb82b or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btmtksdio: Fix out-of-bounds DMA read in the TX path btmtksdio_tx_packet() rounds the transfer size up to the SDIO block size of 256 bytes, but hands the host controller the SKB buffer as is: err = sdio_writesb(bdev->func, MTK_REG_CTDR, skb->data, round_up(skb->len, MTK_SDIO_BLOCK_SIZE)); Only skb->len bytes hold packet data, so the controller reads up to 255 bytes of uninitialised memory and sends it to the device over the SDIO bus. Depending on how much tailroom slack the SKB allocation happens to carry, that read can also extend past the end of the buffer. Compute the padded length up front, ensure the SKB has tailroom for it, and zero-fill the padding with skb_put_zero(). skb->len then covers the padding, so sdio_writesb() no longer needs to round up. byte_tx keeps counting the header and the payload only, and the error path restores the SKB so that the caller can requeue it. Writing behind skb->tail is only safe because the driver owns the buffer, which "Bluetooth: btmtksdio: Take exclusive ownership of the SKB before TX" ensures.

—No exploit Fix available
Published
Sep 17, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 11th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.2affected
    • 9aebfd4a2200ab8075e44379c758bccefdc589bb and later · before c8742f53c9ef623decd5285403df0e5b5273c9fdaffected · git
    • 9aebfd4a2200ab8075e44379c758bccefdc589bb and later · before 0b71a6caaf284915c8cf9cd320ecee9f0361824aaffected · git
    • 9aebfd4a2200ab8075e44379c758bccefdc589bb and later · before 9a785ea864214aaffd8300683825c3f788d0b634affected · git
    • 9aebfd4a2200ab8075e44379c758bccefdc589bb and later · before 7b37556d7d801b79096c7ba8ea92db2338aa8b00affected · git
    • 9aebfd4a2200ab8075e44379c758bccefdc589bb and later · before 7b80d2701a68456c536f82e577dbed2f60ccb82baffected · git
    • 9aebfd4a2200ab8075e44379c758bccefdc589bb and later · before fa0ad2d277c7adead61d1c22411c55cea6990c2aaffected · git
    • before 5.2not affected · semver
    • 6.1.188 and later · up to and including 6.1.*not affected · semver
    • 6.6.157 and later · up to and including 6.6.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-90088Sep 17, 2026 · Bluetooth: RFCOMM: Validate MTU in rfcomm_apply_pn() to prevent infinite loop
    0Monitor
  • ← EarlierCVE-2026-90089Sep 17, 2026 · Bluetooth: btnxpuart: Validate the FW dump header length
    28Monitor
  • Later →CVE-2026-90091Sep 17, 2026 · Bluetooth: L2CAP: fix race l2cap_sock_cleanup_listen() vs. put_chan
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0b71a6caaf284915c8cf9cd320ecee9f0361824aVendor (CNA)
Linux Linux7b37556d7d801b79096c7ba8ea92db2338aa8b00Vendor (CNA)
Linux Linux7b80d2701a68456c536f82e577dbed2f60ccb82bVendor (CNA)
Linux Linux9a785ea864214aaffd8300683825c3f788d0b634Vendor (CNA)
Linux Linuxc8742f53c9ef623decd5285403df0e5b5273c9fdVendor (CNA)
Linux Linuxfa0ad2d277c7adead61d1c22411c55cea6990c2aVendor (CNA)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records