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
CVE-2023-0266
“▲” beside the score: it is higher than NVD's CVSS score.
Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2023-03-30), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 7.9 retained for reference. The 9.0 is the floor for confirmed exploitation, not an impact rating: this CVE's impact severity (EG Severity) is CVSS 7.9 HIGH under NVD CVSS v3. Confidence: HIGH.
- Actively exploited in the wild (CISA-KEV) — the reason this is sooner than the SSVC decision on this page at low or medium mission impact
A fix is available — apply it.
- CVSS v3
- 7.9
- EG Score
- 9.0CRITICALhigh confidence
- EG Risk
- 76EG Risk 76/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity79% × 45%Impact severity (EG Severity): CVSS 7.9 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation100% × 40%Fixed at 100% for a CISA KEV listing: EchelonGraph's rule.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Attend at medium and Act at high mission impact.Exploitation active (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines at low, sooner than that at medium and as soon as possible at high mission impact. - EPSS PROB
- 3.7%
- EPSS %ILE
- 89th
- KEV
- ⚠ Exploited
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (9.0): severity, escalated by confirmed exploitation. This CVE's 9.0 is the CISA KEV floor for confirmed exploitation, not an impact rating: its impact severity (EG Severity) is CVSS 7.9 HIGH.
- EG Severity
- 7.9 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 3.7% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-23). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- CISA KEV and EG-KEV Tier 1 (exploited in the wild)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Attend at medium mission impactTrack at low, Attend at medium and Act at high mission impact.CISA BOD 26-04: 3 days & forensic triage if the affected system is publicly exposed; 14 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Attend at medium and Act at high mission impact.
A fix is available. Apply it within your standard update timelines at low, sooner than that at medium and as soon as possible at high mission impact.
Exploitation active (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)3 days & forensic triage if the affected system is publicly exposed; 14 days if it is not.
In CISA KEV yes (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
CISA required action“Apply updates per vendor instructions.”
Quoted verbatim from CISA's Known Exploited Vulnerabilities catalog. CISA directs it at US federal civilian executive branch agencies under Binding Operational Directive (BOD) 26-04, which replaced BOD 22-01 on 10 June 2026; it is not EchelonGraph's advice. CISA's notes: https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-5.10/alsa-pcm-move-rwsem-lock-inside-snd_ctl_elem_read-to-prevent-uaf.patch?id=72783cf35e6c55bca84c4bb7b776c58152856fd4 · https://nvd.nist.gov/vuln/detail/CVE-2023-0266
Published
January 30, 2023
Last Modified
October 24, 2025
Advisory Details (5)
Auto-updated Oct 19, 2026Known Exploited Vulnerabilities Catalog | CISA
Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-0266[SECURITY] [DLA 3403-1] linux security update
https://lists.debian.org/debian-lts-announce/2023/05/msg00006.htmlcommit becf9e5d553c (torvalds/linux)
Fix landed in torvalds/linux commit becf9e5d553c — awaiting tagged release
https://github.com/torvalds/linux/commit/becf9e5d553c2389d857a3c178ce80fdb34a02e1commit 56b88b50565c (torvalds/linux)
Fix landed in torvalds/linux commit 56b88b50565c — awaiting tagged release
https://github.com/torvalds/linux/commit/56b88b50565cd8b946a2d00b0c83927b7ebb055ealsa-pcm-move-rwsem-lock-inside-snd_ctl_elem_read-to-prevent-uaf.patch « queue-5.10 - kernel/git/stable/stable-queue.git - Linux kernel stable patch queue
https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/tree/queue-5.10/alsa-pcm-move-rwsem-lock-inside-snd_ctl_elem_read-to-prevent-uaf.patch?id=72783cf35e6c55bca84c4bb7b776c58152856fd4Vendor Advisories for CVE-2023-0266(6)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2023:1662Red Hat Product SecurityHigh
Red Hat Security Advisory: kpatch-patch security update
- RHSA-2023:1557Red Hat Product SecurityHigh
Red Hat Security Advisory: kernel security and bug fix update
- RHSA-2023:1554Red Hat Product SecurityHigh
Red Hat Security Advisory: kernel security, bug fix, and enhancement update
- RHSA-2023:1556Red Hat Product SecurityHigh
Red Hat Security Advisory: kernel-rt security and bug fix update
- RHSA-2023:1470Red Hat Product SecurityHigh
Red Hat Security Advisory: kernel security, bug fix, and enhancement update
- CVE-2023-0266Microsoft Security Response Center (MSRC)
CVE-2023-0266
Patch Availability(24)
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(6 across 5 ecosystems)
Debian:10(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| linux | 4.19.118-1 ... 4.19.98-1~bpo9+1 (42 versions) |
| — |
| linux-5.10 | 5.10.136-1~deb10u1, 5.10.136-1~deb10u2, 5.10.136-1~deb10u3, 5.10.149-2~deb10u1, 5.10.158-2~deb10u1 |
| — |
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| linux | 5.10.103-1 ... 5.10.92-2 (24 versions) |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| linux | — |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| linux | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| linux | — |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(19)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
- Red HatRHSA-2023:1202IMPORTANT2023-01-13
RHSA-2023:1202 — Important
- Red HatRHSA-2023:1203IMPORTANT2023-01-13
RHSA-2023:1203 — Important
- Red HatRHSA-2023:1435IMPORTANT2023-01-13
RHSA-2023:1435 — Important
- Red HatRHSA-2023:1469IMPORTANT2023-01-13
RHSA-2023:1469 — Important
- Red HatRHSA-2023:1471IMPORTANT2023-01-13
RHSA-2023:1471 — Important
- Red HatRHSA-2023:1559IMPORTANT2023-01-13
RHSA-2023:1559 — Important
- Red HatRHSA-2023:1560IMPORTANT2023-01-13
RHSA-2023:1560 — Important
- Red HatRHSA-2023:1566IMPORTANT2023-01-13
RHSA-2023:1566 — Important
- Red HatRHSA-2023:1584IMPORTANT2023-01-13
RHSA-2023:1584 — Important
- Red HatRHSA-2023:1588IMPORTANT2023-01-13
RHSA-2023:1588 — Important
- Red HatRHSA-2023:1590IMPORTANT2023-01-13
RHSA-2023:1590 — Important
- Red HatRHSA-2023:1659IMPORTANT2023-01-13
RHSA-2023:1659 — Important
- Red HatRHSA-2023:1660IMPORTANT2023-01-13
RHSA-2023:1660 — Important
- Red HatRHSA-2023:1666IMPORTANT2023-01-13
RHSA-2023:1666 — Important
- Red HatRHSA-2023:1677IMPORTANT2023-01-13
RHSA-2023:1677 — Important
- UbuntuUSN-5915-1HIGH
Linux kernel (OEM) vulnerabilities
- UbuntuUSN-5917-1HIGH
Linux kernel vulnerabilities
- UbuntuUSN-5924-1HIGH
Linux kernel (Azure) vulnerabilities
- UbuntuUSN-5927-1HIGH
Linux kernel (Azure) vulnerabilities
Data Freshness Timeline
(refreshed 29× in last 7d / 298× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 100 of 1,852 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 1,752 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-23 19:28 UTCEG score recompute
- 2026-10-23 19:28 UTCVendor advisory
- 2026-10-23 19:27 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-23 16:29 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-22 20:16 UTCEG score recompute
- 2026-10-22 20:16 UTCVendor advisory
- 2026-10-22 20:16 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-22 16:30 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-21 21:05 UTCEG score recompute
- 2026-10-21 21:05 UTCVendor advisory
- 2026-10-21 21:04 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-21 16:29 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-20 21:56 UTCEG score recompute
- 2026-10-20 21:56 UTCVendor advisory
- 2026-10-20 21:56 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-20 16:29 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-19 22:47 UTCEG score recompute
- 2026-10-19 22:47 UTCVendor advisory
- 2026-10-19 22:47 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-19 16:28 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-18 23:38 UTCEG score recompute
- 2026-10-18 23:38 UTCVendor advisory
- 2026-10-18 23:37 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-18 16:29 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-18 08:18 UTCEG score recompute
Show 75 moreShow fewer
- 2026-10-18 00:27 UTCEG score recompute
- 2026-10-18 00:27 UTCVendor advisory
- 2026-10-18 00:27 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-17 16:29 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-17 01:17 UTCEG score recompute
- 2026-10-17 01:17 UTCVendor advisory
- 2026-10-17 01:17 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-16 16:35 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-16 02:08 UTCEG score recompute
- 2026-10-16 02:08 UTCVendor advisory
- 2026-10-16 02:08 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-15 16:28 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-15 02:57 UTCEG score recompute
- 2026-10-15 02:57 UTCVendor advisory
- 2026-10-15 02:57 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-14 16:29 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-14 03:47 UTCEG score recompute
- 2026-10-14 03:47 UTCVendor advisory
- 2026-10-14 03:47 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-13 16:29 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-13 04:38 UTCVendor advisory
- 2026-10-13 04:38 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-12 18:40 UTCEG score recompute
- 2026-10-12 16:30 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-12 05:29 UTCVendor advisory
- 2026-10-12 05:28 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-12 01:14 UTCVendor advisory
- 2026-10-12 01:14 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-11 21:01 UTCEG score recompute
- 2026-10-11 21:01 UTCVendor advisory
- 2026-10-11 21:01 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-11 16:47 UTCEG score recompute
- 2026-10-11 16:47 UTCVendor advisory
- 2026-10-11 16:46 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-11 13:45 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-11 12:34 UTCEG score recompute
- 2026-10-11 12:34 UTCVendor advisory
- 2026-10-11 12:33 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-11 08:21 UTCVendor advisory
- 2026-10-11 08:20 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-11 04:06 UTCVendor advisory
- 2026-10-11 04:06 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-10 23:53 UTCEG score recompute
- 2026-10-10 23:53 UTCVendor advisory
- 2026-10-10 23:52 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-10 19:57 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-10 19:39 UTCVendor advisory
- 2026-10-10 19:39 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-10 15:26 UTCVendor advisory
- 2026-10-10 15:26 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-10 11:11 UTCVendor advisory
- 2026-10-10 11:10 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-10 06:57 UTCVendor advisory
- 2026-10-10 06:57 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-10 02:44 UTCVendor advisory
- 2026-10-10 02:44 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-09 22:31 UTCEG score recompute
- 2026-10-09 22:31 UTCVendor advisory
- 2026-10-09 22:30 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-09 20:05 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-09 18:17 UTCVendor advisory
- 2026-10-09 18:17 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-09 14:04 UTCVendor advisory
- 2026-10-09 14:04 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-09 09:51 UTCVendor advisory
- 2026-10-09 09:51 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-09 05:37 UTCVendor advisory
- 2026-10-09 05:36 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-09 01:23 UTCVendor advisory
- 2026-10-09 01:23 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-08 21:10 UTCEG score recompute
- 2026-10-08 21:10 UTCVendor advisory
- 2026-10-08 21:10 UTCGHSA enrichmentGHSA-h8jm-3c82-6vvq · GitHub severity HIGH · GitHub CVSS 7.8
- 2026-10-08 17:05 UTCEPSS rescoreEPSS 3.7% · 89th percentile
- 2026-10-08 16:57 UTCVendor advisory
Publicly available exploits
(1 reference)Public exploit code is referenced for this CVE (1 GitHub PoC). Defenders should treat patch urgency accordingly.
- GitHub PoCSeanHeelan/claude_opus_cve_2023_0266Published Mar 10, 2024
Demo showing Claude Opus does not find CVE-2023-0266
Open source ↗
Related CVEs(same vendor + same CWE)
Same vendor
10 shownubuntu:USN-5915-1 · ubuntu:USN-5917-1 · redhat:RHSA-2023:1556
Frequently asked(6)
What is CVE-2023-0266?
When was CVE-2023-0266 made public?
Is CVE-2023-0266 actively exploited?
What is the CVSS score of CVE-2023-0266?
Which products are affected by CVE-2023-0266?
How do I remediate CVE-2023-0266?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-0266
Is Your Infrastructure Affected by CVE-2023-0266?
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