NVD / CVE Program· CNA Linux

CVE-2026-98116: ALSA: pcm: Serialize PCM mmap with buffer reallocation to fix page UAF

Noroxi assessment

Priority: Monitor (action score 31/100)

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: 0.12% (FIRST EPSS).
Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 4.15, 4.20, 5.11; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 4.15, 4.20, 5.11; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1 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: ALSA: pcm: Serialize PCM mmap with buffer reallocation to fix page UAF snd_pcm_hw_params() and snd_pcm_hw_free() guard buffer reallocation with an mmap_count check performed under the PCM stream lock, but the lock is released long before the buffer is actually freed: snd_pcm_sync_stop(), constraint refinement and do_free_pages() all happen in between. snd_pcm_mmap_data(), on the other hand, takes no lock at all: it validates against the old buffer's state and dma_bytes, remaps its pages into the VMA, and only then increments mmap_count. A concurrent mmap() can therefore slip in between the check and the free. remap_pfn_range() installs writable PTEs for the old buffer's pages without taking page references, and the subsequent do_free_pages() returns those pages to the page allocator while the VMA still maps them. This leaves a stale, writable mapping of freed pages: a page-level use-after-free that can be leveraged for local privilege escalation. Make snd_pcm_mmap_data() participate in the buffer-access scheme introduced for hw_params/hw_free: acquire runtime->buffer_accessing before validating and remapping, and release it afterwards. Buffer reallocation already fails with -EBUSY while accessors are active, and the mmap side now fails with -EBUSY while a reallocation is in progress, so the validate/remap sequence and the check/free sequence can no longer interleave. A reproducer that turns this race into a stale writable mapping of the freed DMA buffer pages is available on request.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

EUVD-2026-86947

Published: Sep 25, 2026
Updated: Oct 28, 2026
EPSS: 0.1% · 2th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CNA vs NVD score

NVD: —
CNA · Linux: 7.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

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

If any of these changes, we'll tell you in the daily email digest.

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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.

We use this product, ask for help

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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel4.14.279 and later · before 4.15
linux linux kernel4.19.243 and later · before 4.20
linux linux kernel5.4.193 and later · before 5.5
linux linux kernel5.10.109 and later · before 5.11
linux linux kernel5.15.32 and later · before 5.15.222
linux linux kernel5.16.18 and later · up to 5.17.1 inclusive
linux linux kernel6.7 and later · before 6.12.111
linux linux kernel6.13 and later · before 6.18.53
linux linux kernel6.19 and later · before 7.2.7
linux linux kernel7.3

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
- a42aa926843acca96c0dfbde2e835b8137f2f092, 9cb6c40a6ebe4a0cfc9d6a181958211682cffea9, fbeb492694ce0441053de57699e1e2b7bc148a69, 0f6947f5f5208f6ebd4d76a82a4757e2839a23f8, 0090c13cbbdffd7da079ac56f80373a9a1be0bf8, 1bbf82d9f961414d6c76a08f7f843ea068e0ab7b, 5.18affected
- 33061d0fba51d2bf70a2ef9645f703c33fe8e438 and later · before e6cdd2a0470d64073349a970dc1691433804b271affected · git
- 92ee3c60ec9fe64404dc035e7c41277d74aa26cb and later · before 9857a75714bb5df4781e4d8b1a1753b1e17bf07aaffected · git
- 92ee3c60ec9fe64404dc035e7c41277d74aa26cb and later · before cbadf2575d25e7dcc0d4da2717817ae569fbc99baffected · git
- 92ee3c60ec9fe64404dc035e7c41277d74aa26cb and later · before cbc7ec97601d09b74e05e44470fa6b0bcdabf3f5affected · git
- 92ee3c60ec9fe64404dc035e7c41277d74aa26cb and later · before fd137bf8149bc6460f9b7b1fc292025da04cb9eeaffected · git
- 92ee3c60ec9fe64404dc035e7c41277d74aa26cb and later · before 8c1882dfee8f404d118020664b73eb4592172226affected · git
- 92ee3c60ec9fe64404dc035e7c41277d74aa26cb and later · before 9b110a9dcecc59516c77cb3c0caf1f492f75df2daffected · git
- 5.15.32 and later · before 5.15.222affected · semver
- 4.14.279 and later · before 4.15affected · semver

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.190-1	6.1.190-1
Debian:12	linux-6.12	before 6.12.111-1~deb12u1	6.12.111-1~deb12u1
Debian:13	linux	before 6.12.111-1	6.12.111-1
Debian:14	linux	before 7.2.7-1	7.2.7-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
90Now
CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
89Now
CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
85Now

Published before and after this one in the same product

← EarlierCVE-2026-98114Sep 25, 2026 · ksmbd: propagate DACL parsing errors
22Monitor
← EarlierCVE-2026-98115Sep 25, 2026 · ksmbd: safely drain sessions during logoff
35Monitor
Later →CVE-2026-98117Sep 25, 2026 · cachefiles: Fix potential UAF/KASAN warning
31Monitor

Remediation

Which version to upgrade to

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

Product / package	Fixed version	Source
Linux Linux	4.15	Vendor (CNA)
Linux Linux	4.20	Vendor (CNA)
Linux Linux	5.11	Vendor (CNA)
Linux Linux	5.15.222	Vendor (CNA)
Linux Linux	5.17	Vendor (CNA)
Linux Linux	5.18	Vendor (CNA)
Linux Linux	5.5	Vendor (CNA)
Linux Linux	8c1882dfee8f404d118020664b73eb4592172226	Vendor (CNA)
Linux Linux	9857a75714bb5df4781e4d8b1a1753b1e17bf07a	Vendor (CNA)
Linux Linux	9b110a9dcecc59516c77cb3c0caf1f492f75df2d	Vendor (CNA)
Linux Linux	cbadf2575d25e7dcc0d4da2717817ae569fbc99b	Vendor (CNA)
Linux Linux	cbc7ec97601d09b74e05e44470fa6b0bcdabf3f5	Vendor (CNA)
Linux Linux	e6cdd2a0470d64073349a970dc1691433804b271	Vendor (CNA)
Linux Linux	fd137bf8149bc6460f9b7b1fc292025da04cb9ee	Vendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0	6.6.158.1-1 · Release Notes	Microsoft (MSRC)
debian:linux	6.1.190-1 · Debian:12	Package registry (OSV)
debian:linux	6.12.111-1 · Debian:13	Package registry (OSV)
debian:linux-6.12	6.12.111-1~deb12u1 · Debian:12	Package 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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-26-1184 · Sep 28, 2026(Linux Kernel Güvenlik Bildirimi)

All national notices →

Technical details

Attack conditions

Someone with local access to the system can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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

Fix✗ → ✓Sep 28, 2026, 9:54 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/8c1882dfee8f404d118020664b73eb4592172226

Show all references (6 more)

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

All records