CVE-2025-38595 — xen: fix UAF in dmabuf_exp_from_pages()
In the Linux kernel, the following vulnerability has been resolved: xen: fix UAF in dmabuf_exp_from_pages() [dma_buf_fd() fixes; no preferences regarding the tree it goes through - up to xen folks] As soon as we'd inserted a file reference into descriptor table, another thread could close it. That's fine for the case when all we are doing is returning that descriptor to userland (it's a race, but it's a userland race and there's nothing the kernel can do about it). However, if we follow fd_install() with any kind of access to objects that would be destroyed on close (be it the struct file itself or anything destroyed by its ->release()), we have a UAF. dma_buf_fd() is a combination of reserving a descriptor and fd_install(). gntdev dmabuf_exp_from_pages() calls it and then proceeds to access the objects destroyed on close - starting with gntdev_dmabuf itself. Fix that by doing reserving descriptor before anything else and do fd_install() only when everything had been set up.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ a240d6e42e28c34fdc34b3a98ca838a31c939901 and < ba8bc644f168509c16d48444991de7cfea3f12ec≥ a240d6e42e28c34fdc34b3a98ca838a31c939901 and < e5907885260401bba300d4d18d79875c05b82651≥ a240d6e42e28c34fdc34b3a98ca838a31c939901 and < 3edfd2353f301bfffd5ee41066e37320a59ccc2d≥ a240d6e42e28c34fdc34b3a98ca838a31c939901 and < d59d49af4aeed9a81e673e37c26c6a3bacf1a181≥ a240d6e42e28c34fdc34b3a98ca838a31c939901 and < 532c8b51b3a8676cbf533a291f8156774f30ea87version 4.19 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel | ≥ 4.19 and < 6.12.42≥ 6.13 and < 6.15.10≥ 6.16 and < 6.16.1 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 20, 2026 → Oct 25, 2026 · 6 reading(s) · max 0.22%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- Affected products added · linux/linux kernel
- CVSS changed · 7.8
- Source status changed · → Modified
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 21, 2026 – Oct 21, 2026
- 1× Official description updated · Oct 21, 2026 – Oct 21, 2026
References
7 on the record
- git.kernel.org/stable/c/d59d49af4aeed9a81e673e37c26c6a3bacf1a181
- git.kernel.org/stable/c/e5907885260401bba300d4d18d79875c05b82651
- git.kernel.org/stable/c/3edfd2353f301bfffd5ee41066e37320a59ccc2d
- git.kernel.org/stable/c/532c8b51b3a8676cbf533a291f8156774f30ea87
- git.kernel.org/stable/c/ba8bc644f168509c16d48444991de7cfea3f12ec
- nvd.nist.gov/vuln/detail/CVE-2025-38595
- github.com/advisories/GHSA-43g4-4j68-8xj3
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99092 riscv: patch: fix handling of bpf-jit execmem addresses 12h
- Unknown CVE-2026-99093 mm: don't schedule deferred kernel page table freeing while booting 12h
- Unknown CVE-2026-99095 drm/vc4: drain the hangcheck timer and works on V3D unbind 12h
- Unknown CVE-2026-99096 io_uring/register: don't exempt disabled rings from task restrictions 12h
- Unknown CVE-2026-99097 tee: shm: reject zero-sized allocations in tee_dyn_shm_alloc_helper() 12h
- Unknown CVE-2026-99098 dm-integrity: fix buffer overflow in inline mode with large tag size 12h
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-38595 is "xen: fix UAF in dmabuf_exp_from_pages()", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.22% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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