CVE-2026-23519

Q: How do I fix CVE-2026-23519?

Upgrade cmov to 0.4.4 or later.

Q: Is CVE-2026-23519 being actively exploited?

Not that we know of. CVE-2026-23519 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.50% is the estimated probability that it will be exploited in the next 30 days. That is higher than 40% of all scored CVEs.

Q: How severe is CVE-2026-23519?

CVE-2026-23519 has a CVSS v3 base score of 9.8, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

Q: What does CVE-2026-23519 affect?

Published advisories record a fix for cmov (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

CRITICAL

9.8

CVSS v3

NVD

Description

RustCrypto CMOV provides conditional move CPU intrinsics which are guaranteed on major platforms to execute in constant-time and not be rewritten as branches by the compiler. Prior to 0.4.4, the thumbv6m-none-eabi (Cortex M0, M0+ and M1) compiler emits non-constant time assembly when using cmovnz (portable version). This vulnerability is fixed in 0.4.4.

CWE-208 CWE-203

How to fix

Remediation Available

cmovNVD

Affected:< 0.4.4Fixed in:0.4.4CVE-2026-23519derived from NVD

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

0.50%probability of exploitation in 30 days

40thpercentile

Moderate risk: more likely to be exploited than 40% of all known CVEs.

References

Patch1

github.com

Exploit1

github.com

Related Vulnerabilities

Other CWE-208 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2019-9494	Medium	5.9	3.9%	-	Fix
CVE-2019-16782	Medium	6.3	3.7%	-	Fix
CVE-2025-53940	Unscored	-	2.6%	-	-
CVE-2020-1926	Medium	5.9	2.5%	-	Fix
CVE-2021-43298	Critical	9.8	2.3%	-	Fix
CVE-2024-29995	High	8.1	1.5%	-	Fix

Common questions

How do I fix CVE-2026-23519?

Upgrade cmov to 0.4.4 or later.

Is CVE-2026-23519 being actively exploited?

Not that we know of. CVE-2026-23519 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.50% is the estimated probability that it will be exploited in the next 30 days. That is higher than 40% of all scored CVEs.

How severe is CVE-2026-23519?

CVE-2026-23519 has a CVSS v3 base score of 9.8, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-23519 affect?

Published advisories record a fix for cmov (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-23519

Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-01-23.