VulnerabilityPublished 22 Jan 2026

CVE-2026-23967: JuneAndGreen sm-crypto · Improper Verification of Cryptographic Signature

Affects JuneAndGreen sm-cryptoSource CVE Database V5

Not known to be exploited · CVSS 7.5 High : upgrade to 0.3.14 soon.

Data as of 26 Oct 2026, 12:55 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.3.14

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 22 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade JuneAndGreen sm-crypto to 0.3.14.

Affected software

Product	Affected	Fixed in
JuneAndGreensm-crypto	Affected <0.3.14	Fixed in 0.3.14
npmsm-crypto`pkg:npm/sm-crypto`Other threats	Affected <0.3.14	Fixed in 0.3.14

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

European organizations should immediately audit their use of the sm-crypto library and identify any applications employing SM2 signatures. The primary mitigation is to upgrade all instances of sm-crypto to version 0.3.14 or later, where the signature malleability issue is fixed. For applications where upgrading is not immediately feasible, implement additional signature verification layers or use alternative cryptographic libraries with robust SM2 implementations. Conduct thorough testing to ensure that signature verification logic correctly rejects malleable signatures. Monitor for any suspicious activities involving signature forgery attempts. Additionally, review cryptographic policies to assess the necessity of using SM2 and consider fallback or migration strategies to more widely vetted cryptographic standards if appropriate. Establish incident response plans to address potential signature forgery incidents. Finally, maintain awareness of future updates or advisories related to sm-crypto and Chinese cryptographic algorithm implementations.

Description

CVE-2026-23967 is a high-severity vulnerability in the sm-crypto JavaScript library implementing Chinese cryptographic algorithms SM2, SM3, and SM4. The flaw lies in the SM2 signature verification logic prior to version 0.3.14, allowing an attacker to create a new valid signature from an existing one due to signature malleability. This vulnerability does not impact confidentiality or availability but compromises signature integrity, enabling potential forgery of signed messages without requiring authentication or user interaction. No known exploits are currently reported in the wild. The issue is patched in version 0.3.14. European organizations using sm-crypto in applications that rely on SM2 signatures should urgently update to the fixed version to prevent signature forgery risks.

Impact

For European organizations, the primary impact is the risk of signature forgery, which can lead to unauthorized actions being accepted as legitimate if the system relies on SM2 signatures for critical operations such as document signing, software updates, or secure communications. This could undermine trust in digital transactions and cause legal or financial repercussions. Since sm-crypto is a JavaScript library, the vulnerability could affect web applications, browser-based tools, or Node.js services that implement SM2 signatures. Organizations using Chinese cryptographic standards due to regulatory, business, or interoperability reasons are particularly at risk. The lack of confidentiality or availability impact means data leakage or service disruption is unlikely, but the integrity compromise can facilitate fraud, impersonation, or bypass of security controls. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits given the public disclosure.

CWE-347Improper Verification of Cryptographic Signature (opens in a new tab)
Base weaknessOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
OWASP Cheat Sheets
XML Security (opens in a new tab)
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
REST Assessment (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.2 (opens in a new tab)
V3.5.3 (opens in a new tab)
V13.2.6 (opens in a new tab)
Attack patterns
Padding Oracle Crypto Attack (opens in a new tab)
Signature Spoofing by Improper Validation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/JuneAndGreen/sm-crypto/security/advisories/GHSA-qv7w-v773-3xqm (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 29 Jan 2026, 08:49 UTC

WeaknessesCWE-347

Technical details

References

Community reviews

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