CVE-2023-0266
A use after free vulnerability exists in the ALSA PCM package in the Linux Kernel. SNDRV_CTL_IOCTL_ELEM_{READ|WRITE}32 is missing locks that can be used in a use-after-free that can result in a priviledge escalation to gain ring0 access from the system user. We recommend upgrading past commit 56b88b50565cd8b946a2d00b0c83927b7ebb055e
- CVSS
- 7.9Highscored by the publisher (CNA)
- Exploited in the wild
- Yes, in CISA KEV since 30 Mar 2023CISA deadline for US federal agencies: 20 Apr 2023unvetted proof-of-concept code on github
- EPSS
- 2.6%chance of exploitation in the next 30 daystop 15% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 30 Jan 2023analysed here 12 Nov 2026
Do first. Apply updates per vendor instructions. (CISA's required action for this KEV entry)
Summary
Triage
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| Linux Linux Kernel | >= 4.14 and < 56b88b50565cd8b946a2d00b0c83927b7ebb055eVendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- debian:debian_linux
- linux:linux_kernel
Fix and mitigation
WAF and other mitigations
Can a WAF block it? No. The vulnerability is in the Linux kernel's ALSA PCM package and requires local access to trigger a use-after-free condition. It is not exploitable via HTTP requests, so a web application firewall cannot detect or block it.
Also consider: patch
Based on an AI reading of the CVE description, and no vendor rule found yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 30 Mar 2023.
- CISA due date
- 20 Apr 2023, the remediation deadline for US federal agencies
- CISA required action
- Apply updates per vendor instructions.
- Public exploit code
- Unvetted proof-of-concept code on GitHub: 1 GitHub proof of concept
- CISA SSVC
- exploitation active, automatable no, technical impact totalAssessed by CISA 29 Jan 2025 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
GitHub proofs of concept
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 30 Jan 2023Published
- 30 Mar 2023Added to CISA KEV (exploited in the wild)58 days later
- 20 Apr 2023CISA remediation due date (US federal agencies)21 days later
- 10 Mar 2024First proof-of-concept repository on GitHub (unvetted)325 days (about 11 months) later
- 29 Jan 2025CISA SSVC assessment: exploitation active326 days (about 11 months) later
- 21 Oct 2025CVE record last updated265 days (about 9 months) later
- 12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later
CVSS vector
CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:H
| Metric | Value | What it means |
|---|---|---|
| Attack vector | AdjacentSame subnet or link layer. | Same subnet or link layer. |
| Attack complexity | HighNeeds specific conditions, a race or a particular configuration. | Needs specific conditions, a race or a particular configuration. |
| Privileges required | LowThe attacker needs basic user privileges. | The attacker needs basic user privileges. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | ChangedImpact crosses a security boundary into other components. | Impact crosses a security boundary into other components. |
| Confidentiality | LowPartial data disclosure. | Partial data disclosure. |
| Integrity | HighComplete modification possible. | Complete modification possible. |
| Availability | HighFull outage possible. | Full outage possible. |
Common questions
Is CVE-2023-0266 being exploited?
Yes. CVE-2023-0266 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2023-0266?
CVE-2023-0266 is rated High with a CVSS score of 7.9. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2023-0266?
Yes. A fix has been recorded for CVE-2023-0266. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2023-0266 affect?
CVE-2023-0266 affects debian:debian_linux, linux:linux_kernel. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
5 references in the CVE record, grouped by the tags the record gives them.
Other links (5)
- github.com /torvalds/linux/commit/becf9e5d553c2389d857a3c178ce80fdb34a02e1
- git.kernel.org /pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-5.10/alsa-pcm-move-
- github.com /torvalds/linux/commit/56b88b50565cd8b946a2d00b0c83927b7ebb055e
- lists.debian.org /debian-lts-announce/2023/05/msg00006.html
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-0266
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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