CVE-2026-77696

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Source
https://cve.org/CVERecord?id=CVE-2026-77696
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-77696.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-77696
Downstream
Published
2026-09-29T15:32:22Z
Modified
2026-09-30T08:06:06Z
Severity
  • 3.7 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
Summary
Timing Side-Channel in SM2 Signature Generation
Details

Issue summary: SM2 signature generation uses non-constant-time arithmetic on secret values, forming a timing side-channel.

Impact summary: An attacker able to measure SM2 signing times may learn information about the per-signature secret nonce, which over many signatures can, via a lattice / Hidden Number Problem attack, lead to recovery of the private key.

CWE: CWE-208: Observable Timing Discrepancy

Description: SM2 signature generation computes the signature value using variable-time BIGNUM operations on the secret nonce and the private key, so the time taken to produce an SM2 signature depends on these secret values, forming a timing side-channel.

Applications performing SM2 signature generation are affected on all platforms.

FIPS Impact: no SM2 is not a FIPS algorithm.

Database specific 
{
    "cna_assigner":  "openssl",
    "cwe_ids":  [
        "CWE-208"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77696.json",
    "unresolved_ranges":  [
        {
            "extracted_events":  [
                {
                    "introduced":  "4.0.0"
                },
                {
                    "fixed":  "4.0.3"
                },
                {
                    "introduced":  "3.6.0"
                },
                {
                    "fixed":  "3.6.5"
                },
                {
                    "introduced":  "3.5.0"
                },
                {
                    "fixed":  "3.5.9"
                },
                {
                    "introduced":  "3.4.0"
                },
                {
                    "fixed":  "3.4.8"
                },
                {
                    "introduced":  "3.0.0"
                },
                {
                    "fixed":  "3.0.23"
                }
            ],
            "source":  "AFFECTED_FIELD"
        }
    ]
}
References

Affected packages

Git / github.com/openssl/openssl

Affected ranges

Type
GIT
Repo
https://github.com/openssl/openssl
Events
Introduced
e04bd3433fd84e1861bf258ea37928d9845e6a86
Fixed
e04bd3433fd84e1861bf258ea37928d9845e6a86
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "1.1.1"
        },
        {
            "fixed":  "1.1.1zj"
        }
    ],
    "source":  "AFFECTED_FIELD"
}

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-77696.json"
vanir_signatures 
[
    {
        "deprecated":  false,
        "digest":  {
            "line_hashes":  [
                "28170854778703993674264004058177114599",
                "73132526844288570625317440636111911761",
                "177405411499435185068645597737938634778",
                "224809958623850711330610094965797758930",
                "295554444428855106393106961197201359586"
            ],
            "threshold":  0.9
        },
        "id":  "CVE-2026-77696-c377fa22",
        "signature_type":  "Line",
        "signature_version":  "v1",
        "source":  "https://github.com/openssl/openssl/commit/e04bd3433fd84e1861bf258ea37928d9845e6a86",
        "target":  {
            "file":  "include/openssl/opensslv.h"
        }
    }
]
vanir_signatures_modified 
"2026-09-30T08:06:06Z"