Ciphertext forgery via infinity-point acceptance
Published Mar 13, 2026 · Updated Mar 13, 2026
Ciphertext forgery in emmansun GMSM before 0.41.1 allows remote attackers to make SM9 decryption accept chosen plaintext via a forged C1 point. The shared UnwrapKey path deserializes C1 and checks that it lies on the curve but fails to reject the point at infinity, so pairing collapses to the GT identity and makes key-derivation input predictable. Knowledge of the target UID and delivery of forged ciphertext to a recipient invoking SM9 decryption are sufficient; the demonstrated consequence is accepted attacker-chosen plaintext, not disclosure of existing plaintext.
Summary
What happened
Ciphertext forgery in emmansun GMSM before 0.41.1 allows remote attackers to make SM9 decryption accept chosen plaintext via a forged C1 point. The shared UnwrapKey path deserializes C1 and checks that it lies on the curve but fails to reject the point at infinity, so pairing collapses to the GT identity and makes key-derivation input predictable. Knowledge of the target UID and delivery of forged ciphertext to a recipient invoking SM9 decryption are sufficient; the demonstrated consequence is accepted attacker-chosen plaintext, not disclosure of existing plaintext.
The record
- CVE
- CVE-2026-32614
- Published
- Mar 13, 2026
- Updated
- Mar 13, 2026
- Vendor
- emmansun
- Product
- GMSM
- Classifications
- CWE-347, T1565.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 13, 2026CVE publishedPublication date reported by the CVE source.
- Mar 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.41.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Infinity-point SM9 ciphertext forgery testproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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