CVE-2026-54875
Issue summary: A non-constant-time optimized implementation of scalar point multiplication is used for SM2 private key operations on ARM64 and RISC-V platforms.
Impact summary: An attacker able to measure the time taken by, or to observe the cache-line access pattern of SM2 signing or decryption on an affected platform can learn information about the secret scalar.
CWE: CWE-208: Observable Timing Discrepancy
Description: On ARM64 and RISC-V processors, the SM2 curve uses an optimized scalar multiplication implementation whose conditional branches and table look ups are chosen according to the bits of the secret scalar.
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The execution time and the cache-access pattern therefore depend on the long-term private key (during SM2 decryption) or the per-signature nonce (during SM2 signature generation), forming a timing and cache side-channel.
FIPS Impact: no SM2 is not a FIPS algorithm and the optimized SM2 implementation is not part of the FIPS module.
OpenSSL 4.0, 3.6, 3.5 and 3.4 are vulnerable to this issue on AArch64 and RISC-V.
OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.
OpenSSL 4.0 users should upgrade to OpenSSL 4.0.3. OpenSSL 3.6 users should upgrade to OpenSSL 3.6.5. OpenSSL 3.5 users should upgrade to OpenSSL 3.5.9. OpenSSL 3.4 users should upgrade to OpenSSL 3.4.8.
This issue was reported on 2 May 2026 by Abhinav Agarwal. It was independently reported on 6 June 2026 by Feng Xue. The fix was developed by Igor Ustinov.
-- cut (non-publishing metadata for internal use) -- Reported by: Abhinav Agarwal, Feng Xue Fixed by: Igor Ustinov
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
- Puntuación base: 3.7
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.29%
- Percentil entre todas las CVEs puntuadas: 20
- Fecha de la puntuación: 2/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access60 % - Impacto principal
T1552.007Container APIcredential access75 %
Explotación corregida por reglas (vector CVSS): era T1212
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-208
Referencias
- https://github.com/openssl/openssl/commit/3f01bbc28f7e08211fcdc797fd43816504f94257
- https://github.com/openssl/openssl/commit/469f3e42629f4a0b5631796e20c66c92c138a3e8
- https://github.com/openssl/openssl/commit/9794ed473764839275cb701b4850f3c24d929c28
- https://github.com/openssl/openssl/commit/dddad955d5ff3e9507619cf4e0f13e9988e2197c
- https://openssl-library.org/news/secadv/20260929.txt
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-54875",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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"id": "CVE-2026-54875",
"role": "CISA Coordinator",
"options": [
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"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
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"version": "2.0.3",
"timestamp": "2026-09-29T17:17:05.164162Z"
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"cvssMetricV31": [
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"type": "Secondary",
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"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 3.7,
"attackVector": "NETWORK",
"baseSeverity": "LOW",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
},
"impactScore": 1.4,
"exploitabilityScore": 2.2
}
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"affected": [
{
"source": "openssl-security@openssl.org",
"affectedData": [
{
"vendor": "OpenSSL",
"product": "OpenSSL",
"versions": [
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"status": "affected",
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"lessThan": "4.0.3",
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"published": "2026-09-29T16:17:08.920",
"references": [
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"source": "openssl-security@openssl.org"
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{
"url": "https://openssl-library.org/news/secadv/20260929.txt",
"source": "openssl-security@openssl.org"
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"vulnStatus": "Awaiting Analysis",
"weaknesses": [
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"type": "Secondary",
"source": "openssl-security@openssl.org",
"description": [
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"descriptions": [
{
"lang": "en",
"value": "Issue summary: A non-constant-time optimized implementation of scalar\npoint multiplication is used for SM2 private key operations on ARM64 and\nRISC-V platforms.\n\nImpact summary: An attacker able to measure the time taken by, or to observe\nthe cache-line access pattern of SM2 signing or decryption on an affected\nplatform can learn information about the secret scalar.\n\nCWE: CWE-208: Observable Timing Discrepancy\n\nDescription: On ARM64 and RISC-V processors, the SM2 curve uses an optimized\nscalar multiplication implementation whose conditional branches and table\nlook ups are chosen according to the bits of the secret scalar. The execution\ntime and the cache-access pattern therefore depend on the long-term private\nkey (during SM2 decryption) or the per-signature nonce (during SM2 signature\ngeneration), forming a timing and cache side-channel.\n\nFIPS Impact: no\nSM2 is not a FIPS algorithm and the optimized SM2 implementation is not part\nof the FIPS module.\n\nOpenSSL 4.0, 3.6, 3.5 and 3.4 are vulnerable to this issue on AArch64 and\nRISC-V.\n\nOpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.\n\nOpenSSL 4.0 users should upgrade to OpenSSL 4.0.3.\nOpenSSL 3.6 users should upgrade to OpenSSL 3.6.5.\nOpenSSL 3.5 users should upgrade to OpenSSL 3.5.9.\nOpenSSL 3.4 users should upgrade to OpenSSL 3.4.8.\n\nThis issue was reported on 2 May 2026 by Abhinav Agarwal.\nIt was independently reported on 6 June 2026 by Feng Xue.\nThe fix was developed by Igor Ustinov.\n\n-- cut (non-publishing metadata for internal use) --\nReported by: Abhinav Agarwal, Feng Xue\nFixed by: Igor Ustinov"
}
],
"lastModified": "2026-09-29T21:27:41.130",
"sourceIdentifier": "openssl-security@openssl.org"
}