CVE-2026-22698VulnerabilityPublished 10 Jan 2026Updated 12 Jan 2026

CVE-2026-22698: RustCrypto elliptic-curves · Insufficient Entropy

Affects RustCrypto elliptic-curvesSource CVE Database V5

Not known to be exploited · CVSS 8.7 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

8.7High

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 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 2026-10-25.

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 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

Affected software

Product	Affected	Fixed in
RustCryptoelliptic-curves	Affected =0.14.0-pre.0 =0.14.0-rc.0	Fixed in–
crates.iosm2`pkg:cargo/sm2`Other threats	Affected =0.14.0-pre.0 =0.14.0-rc.0	Fixed in–

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 identify and inventory all systems and applications using RustCrypto elliptic-curves versions 0.14.0-pre.0 or 0.14.0-rc.0, focusing on those employing SM2 encryption. The primary mitigation is to upgrade to the latest patched version of the RustCrypto elliptic-curves library where the nonce generation bug is fixed (commit e4f7778 or later). If upgrading is not immediately feasible, organizations should consider disabling or replacing SM2 encryption with alternative, secure cryptographic algorithms until patched versions can be deployed. Conduct thorough code and dependency audits to detect indirect usage of vulnerable versions via third-party libraries. Implement network monitoring to detect unusual cryptographic traffic patterns that may indicate exploitation attempts. Additionally, enforce strict cryptographic policy management to prevent deployment of vulnerable library versions in production. Finally, ensure that cryptographic keys and encrypted data potentially exposed by this vulnerability are rotated or re-encrypted after patching to mitigate risks from past exposures.

Description

RustCrypto: Elliptic Curves is general purpose Elliptic Curve Cryptography (ECC) support, including types and traits for representing various elliptic curve forms, scalars, points, and public/secret keys composed thereof. In versions 0.14.0-pre.0 and 0.14.0-rc.0, a critical vulnerability exists in the SM2 Public Key Encryption (PKE) implementation where the ephemeral nonce k is generated with severely reduced entropy. A unit mismatch error causes the nonce generation function to request only 32 bits of randomness instead of the expected 256 bits. This reduces the security of the encryption from a 128-bit level to a trivial 16-bit level, allowing a practical attack to recover the nonce k and decrypt any ciphertext given only the public key and ciphertext. This issue has been patched via commit e4f7778.

Impact

For European organizations, the impact of this vulnerability is significant, particularly for those utilizing RustCrypto's elliptic-curves library in their cryptographic stacks, especially where SM2 encryption is employed. The compromised nonce entropy allows attackers to decrypt sensitive communications or data, undermining confidentiality guarantees. This can lead to exposure of personal data, intellectual property, or sensitive business information, potentially violating GDPR and other data protection regulations. Industries such as finance, telecommunications, government, and critical infrastructure that rely on strong ECC-based encryption are at heightened risk. The ease of exploitation and lack of required authentication mean attackers can remotely compromise encrypted data without insider access. This vulnerability could also erode trust in cryptographic implementations and cause operational disruptions if exploited. Although no active exploits are known, the vulnerability's presence in widely used cryptographic libraries necessitates urgent remediation to prevent future attacks.

Summary

The vulnerability identified as CVE-2026-22698 affects RustCrypto's elliptic-curves library, specifically versions 0.14.0-pre.0 and 0.14.0-rc.0. The flaw lies in the SM2 Public Key Encryption (PKE) implementation where the ephemeral nonce k, critical for ensuring the security of each encryption operation, is generated with insufficient entropy. This is caused by a unit mismatch error in the nonce generation function, which requests only 32 bits of randomness instead of the intended 256 bits. As a result, the effective security level of the encryption is drastically reduced from the expected 128-bit strength to roughly 16 bits, making brute-force or cryptanalytic recovery of the nonce feasible with modest computational effort. Once the nonce k is recovered, an attacker can decrypt any ciphertext encrypted under the same public key without needing the private key. The vulnerability requires no privileges, no authentication, and no user interaction, and can be exploited remotely by an attacker with access to the ciphertext and public key. This weakness compromises the confidentiality of encrypted communications or data protected by the affected SM2 implementation. The issue has been addressed and patched in subsequent versions of the library, with the fix committed in e4f7778. No known exploits have been reported in the wild to date, but the vulnerability's nature and severity make it a critical concern for any system relying on these specific RustCrypto versions for elliptic curve cryptography.

CWE-331Insufficient Entropy (opens in a new tab)
Base weaknessOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.
Implementation
Determine the necessary entropy to adequately provide for randomness and predictability. This can be achieved by increasing the number of bits of objects such as keys and seeds.
OWASP Cheat Sheets
Session Management (opens in a new tab)
Transport Layer Protection (opens in a new tab)
User Privacy Protection (opens in a new tab)
Password Storage (opens in a new tab)
Cryptographic Storage (opens in a new tab)
OWASP ASVS 4.0.3
V3.2.2 (opens in a new tab)
V3.2.4 (opens in a new tab)
V2.3.1 (opens in a new tab)
Attack patterns
Session Credential Falsification through Prediction (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Jan 2026, 07:55 UTC

WeaknessesCWE-331

Technical details

References

Community reviews

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