CVE-2026-19737

MEDIUMPre-NVD 5.55.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This medium-severity CVE scores 5.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1% (below the 1st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 3 sources updated this week
5.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

i2s_esp32_trigger_check() in drivers/i2s/i2s_esp32.c validates the requested direction only for I2S_DIR_BOTH. The I2S_DIR_RX and I2S_DIR_TX branches read dev_cfg->rx.data->configured / dev_cfg->tx.data->configured without first checking the stream pointers. The device instantiation macro I2S_ESP32_STREAM_INIT() sets both .conf and .data to NULL for a direction the devicetree does not describe, so on an instance that wires only one direction — the normal shape for audio output or a worldsemi,ws2812-i2s LED strip — the other direction dereferences a NULL pointer instead of returning an error.

i2s_trigger() is a Zephyr syscall, and z_vrfy_i2s_trigger() in drivers/i2s/i2s_handlers.c validates only the device object and the presence of the trigger API pointer; the dir argument is passed to the driver unvalidated. On a build with CONFIG_USERSPACE enabled, a user-mode thread that has been granted the I2S device can issue a single i2s_trigger() call naming the unwired direction and cause a load from address 0 in kernel mode. Among the Espressif parts that carry this driver, userspace is available in-tree only on RISC-V SoCs with CONFIG_RISCV_PMP, and v4.4.0 is the first release where that is buildable: the ESP32-C6 HPCORE selects RISCV_PMP when it is not built for MCUboot. ESP32-C5 in v4.4.x carries the same PMP-region and userspace linker support but does not select RISCV_PMP by default. Espressif Xtensa targets do not support Zephyr userspace, and in a non-userspace build the bad direction can only come from in-kernel application code.

The impact is limited to availability: the access is a read at offset 0 of the missing stream structure, so there is no attacker-controlled offset, no write primitive and no information disclosure. With the default fatal-error handler the resulting exception halts the system, giving an unprivileged user-mode thread a system-wide denial of service. The fix adds the same pointer check the I2S_DIR_BOTH branch already performed and returns -ENOSYS for a direction the instance does not implement; the driver's other entry points (i2s_esp32_config_check(), i2s_esp32_config_get(), i2s_esp32_read(), i2s_esp32_write()) already guarded the pointers, and a static audit found no equivalent unguarded path.

The driver defect is older than the affected range. The unguarded dereference is present from v4.2.0 (reached through i2s_esp32_trigger_stream(), whose if (stream) guard tests the address of a struct member and is never false) and takes its present i2s_esp32_trigger_check() form in v4.3.0. No in-tree Espressif configuration before v4.4.0 can run a user-mode thread, so in v4.2.x and v4.3.x the direction argument can only come from trusted kernel code. Those releases carry the bug but are not listed as affected; the fix has also been merged to v4.3-branch as hardening.

CVSS v3
5.5
EG Score
5.5MEDIUMmedium confidence
EG Risk
25
EG Risk 25/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed (value × EchelonGraph’s weight)
Severity55% × 45%
The EG Score, 5.5 of 10.
Exploitation0.1% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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 referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation.
EPSS PROB
0.1%
EPSS %ILE
below the 1st
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is referenced, but no release containing it is confirmed. Check the referenced fix and the vendor's advisory for a release that contains it and apply that within your standard update timelines; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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

Published

October 11, 2026

Last Modified

October 13, 2026

Advisory Details (2)

Auto-updated Oct 11, 2026
Fix referenced — no release confirmed yet. Sources: github_commit, github.
GitHub advisoryMentions a patch (unverified)

NULL pointer dereference in the ESP32 I2S driver when triggering an unsupported direction · Advisory · zephyrproject-rtos/zephyr · GitHub

https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-5g9q-h8wq-rrf3
GitHub commit

commit 0d82dbbe72f1 (zephyrproject-rtos/zephyr)

Fix landed in zephyrproject-rtos/zephyr commit 0d82dbbe72f1 — awaiting tagged release

https://github.com/zephyrproject-rtos/zephyr/commit/0d82dbbe72f154de32cc45021a9f59d9a737246b

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 8× 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.

  1. 2026-10-13 17:07 UTCEG score recompute
  2. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.1% · below the 1st percentile
  3. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.1% · below the 1st percentile
  4. 2026-10-12 16:25 UTCEG score recompute
  5. 2026-10-11 20:06 UTCEG score recompute
  6. 2026-10-11 18:27 UTCEG score recompute
  7. 2026-10-11 17:27 UTCEG score recomputeFirst assessed: 5.5 MEDIUM
  8. 2026-10-11 17:25 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-19737?
CVE-2026-19737 is a medium-severity vulnerability; its CVE record was published on October 11, 2026. i2sesp32triggercheck() in drivers/i2s/i2sesp32.c validates the requested direction only for I2SDIRBOTH. The I2SDIRRX and I2SDIRTX branches read devcfg->rx.data->configured / devcfg->tx.data->configured without first checking the stream pointers. The device instantiation macro I2SESP32STREAM_INIT()…
When was the CVE record for CVE-2026-19737 published?
The CVE record for CVE-2026-19737 was published on October 11, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 13, 2026; the record at its source may have been updated since.
Is CVE-2026-19737 actively exploited?
CVE-2026-19737 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (below the 1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-19737?
CVE-2026-19737 has a CVSS base score of 5.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-19737?
A fix for CVE-2026-19737 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation.

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