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CVE-2025-39790

Exploitation: none CVSS 8.4 HIGH

CVSS base score: 8.4 (High) vendor CNA · v3.1

Score assigned by the vendor's own CVE Numbering Authority (CNA); CISA's Vulnrichment program adds a score only when the CNA omits one. Vulnrichment source record →

Vendor: Linux   Product: Linux

Description

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: host: Detect events pointing to unexpected TREs When a remote device sends a completion event to the host, it contains a pointer to the consumed TRE. The host uses this pointer to process all of the TREs between it and the host's local copy of the ring's read pointer. This works when processing completion for chained transactions, but can lead to nasty results if the device sends an event for a single-element transaction with a read pointer that is multiple elements ahead of the host's read pointer. For instance, if the host accesses an event ring while the device is updating it, the pointer inside of the event might still point to an old TRE. If the host uses the channel's xfer_cb() to directly free the buffer pointed to by the TRE, the buffer will be double-freed. This behavior was observed on an ep that used upstream EP stack without 'commit 6f18d174b73d ("bus: mhi: ep: Update read pointer only after buffer is written")'. Where the device updated the events ring pointer before updating the event contents, so it left a window where the host was able to access the stale data the event pointed to, before the device had the chance to update them. The usual pattern was that the host received an event pointing to a TRE that is not immediately after the last processed one, so it got treated as if it was a chained transaction, processing all of the TREs in between the two read pointers. This commit aims to harden the host by ensuring transactions where the event points to a TRE that isn't local_rp + 1 are chained. [mani: added stable tag and reworded commit message]

Research & News Coverage

No mentions found in monitored research blogs or news feeds.

Referenced in Advisories

DateAdvisoryIssuer
2026-05-14 ICSA-26-134-10: Siemens SIMATIC CISA

Lifecycle Timeline

Each milestone comes from a different source, so gaps between them are gaps in what those sources publish, not evidence that nothing happened. EPSS history for this CVE holds 3 points from 2026-11-05, tracked daily from 2026-11-05; earlier points are weekly, which dates a spike to within a week. Peak probability 0.2% on 2026-11-05.

Published Applicability

Red Hat CSAF/VEX 158 affected · 0 fixed · 42 not affected
OSV.dev (incl. GHSA) 11 affected · 11 fixed · 0 not affected
CVE List v5 (CNA container) 7 affected · 0 fixed · 7 not affected
CVE List v5 (ADP/Vulnrichment) 1 affected · 0 fixed · 0 not affected

Check whether a specific version is affected →

What each source publishes about which product versions carry this vulnerability, kept as written rather than merged. Absence here means no source has published applicability data, not that nothing is affected.

Detection & Exploitation

Scan
none published
Exploit / Pen Test
none published
Network IDS/IPS
none published
Host / SIEM
none published

Blind spot. No public detection — verify by version/patch. Nothing in the monitored scanner, IDS, SIEM or offensive-tool collections references this CVE, so exposure has to be established from asset inventory and patch level rather than from a signature.

Coverage across public collections only: Nuclei and OpenVAS NVT (scan); Snort and Suricata ET Open (network); Sigma and YARA (host/SIEM); Metasploit, Exploit-DB, public GitHub repositories and NVD exploit references (exploit). Absence here means nothing public was found, not that detection is impossible.
GitHub PoC repositories are collected automatically by PoC-in-GitHub (CC0) and filtered to repositories that are still online, contain code, and are starred or at least two weeks old. They are still not vetted: some are fakes and some are malware. Treat them as evidence that code was published, not as code to run.
NVD exploit references are links NVD's analysts tag as exploits; they confirm an exploit was referenced but carry no date. This product uses data from the NVD but is not endorsed or certified by the NVD.
OpenVAS coverage derives from the Greenbone Community Feed, made available under the Open Database License (ODbL) v1.0; its individual Vulnerability Tests are licensed GNU GPL v2.

No exploit-tool sightings recorded for this CVE.

Metasploit is dated by the first commit of the module file, Exploit-DB by its publication date, and GitHub repositories by their creation date. GitHub PoC repositories are filtered (still online, contain code, starred or at least two weeks old) but not vetted: some are fakes and some are malware, so they show that code was published, not that it works or is safe to run. Evidence tiers are explained on the About page.

Distribution Status

Debian · linux bookworm 6.1.153-1 trixie 6.12.48-1 forky 6.16.5-1 sid 6.16.5-1 scope: local

Where the distribution has shipped a fix, and in which version. Green means the release has resolved it, amber that it is still open. Data from the Debian Security Tracker, used under Debian's MIT / GPLv2+ terms. Debian is upstream of several other distributions, so a fix here often precedes theirs.

CISA Assessment (Vulnrichment / SSVC)

none
no
total
—
8.4 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
2026-10-15

Federal Remediation Window (BOD 26-04)

No
no
total control
If the asset isRemediate withinTable 1 row
Publicly exposed 14 days 7 of 16
Not publicly exposed Fix on system upgrade 15 of 16

BOD 26-04 replaced the single KEV deadline of BOD 22-01 with four inputs: whether the asset is publicly exposed, KEV status, whether exploitation is automatable, and technical impact. Exposure belongs to each agency's asset, not to the CVE, so both outcomes are shown. Automatable and technical impact come from the CISA assessment above. Days are calendar days; for KEV entries the clock starts on the date it was added, and otherwise when the agency identifies the vulnerability on an asset. Agencies make the final exposure call asset by asset, and may set shorter timelines.

External References