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TI-2026-39656 Aliases CVE-2026-54875GHSA-q4gq-r6f8-q6q9

Non-Constant-Time SM2 Scalar Multiplication on ARM64 and RISC-V

Priority LOW 18CWE-208Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
Partial Red Hat: 1 fixed, 7 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-208.

Summary

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. 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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00479 41st percentileScored 2026-11-07
Fix Partial OpenSSL (OpenSSL): 4.0.3, 3.6.5, 3.5.9 +1Red Hat: 2 advisoriesRed Hat: 1 fixed, 7 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
OpenSSLOpenSSL4.0.0 to before 4.0.3; 3.6.0 to before 3.6.5; 3.5.0 to before 3.5.9; 3.4.0 to before 3.4.84.0.3, 3.6.5, 3.5.9, 3.4.8Patch availableCNA
  • OpenSSL VendorOpenSSL Affected 4.0.0 to before 4.0.3; 3.6.0 to before 3.6.5; 3.5.0 to before 3.5.9; 3.4.0 to before 3.4.8 Fixed in 4.0.3, 3.6.5, 3.5.9, 3.4.8 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:*3.4.0 to before 3.4.8; 3.5.0 to before 3.5.9; 3.6.0 to before 3.6.5; 4.0.0 to before 4.0.3VulnerableOpenSSL
  • cpe:2.3:a:openssl:openssl:*:*:*:*:*:*:*:* Versions 3.4.0 to before 3.4.8; 3.5.0 to before 3.5.9; 3.6.0 to before 3.6.5; 4.0.0 to before 4.0.3 Vulnerable ·OpenSSL

Remediation

  • Fix · CNA OpenSSL (OpenSSL) Fixed in 4.0.3, 3.6.5, 3.5.9, 3.4.8

Red Hat 2 advisories

  • RHSA-2026:74166 Released 2026-09-30 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images openssl3-1:3.5.9-0.1.hum1@src, openssl3-devel-1:3.5.9-0.1.hum1@aarch64, openssl3-devel-1:3.5.9-0.1.hum1@x86_64 +4
  • RHSA-2026:74162 Released 2026-09-30 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images openssl-1:3.5.9-0.1.hum1@aarch64, openssl-1:3.5.9-0.1.hum1@src, openssl-1:3.5.9-0.1.hum1@x86_64 +12

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    OpenSSL — openssl-library.org/news/secadv/20260929.txt

    14 records Highest priority Priority MEDIUM 3 MEDIUM, 11 LOW

    Other records, highest priority first

    • TI-2026-58283 DTLS Retransmits Handshake Messages From a Stale Buffer OffsetPriority MEDIUM 43
    • TI-2026-58285 QUIC: Unbounded RETIRE_CONNECTION_ID BacklogPriority MEDIUM 40
    • TI-2026-39654 QUIC STREAM Fragment Metadata DoSPriority MEDIUM 40
    Show all 14 records → Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Developer Hub 1AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat OpenShift AI (RHOAI)Affected—
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Red Hat Satellite 6AffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:74162, RHSA-2026:74166
Not affected: 6 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Hardened Images
  • Red Hat JBoss Core Services
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-54875
  2. 2026-10-03 Alias added: GHSA-q4gq-r6f8-q6q9
  3. 2026-10-16 Affected versions changed · Red Hat
  4. 2026-10-27 Affected versions changed · Red Hat
  5. 2026-10-30 Affected versions changed · Red Hat
  6. 2026-11-06 Affected versions changed · Red Hat

References

Patch 4

Advisory 1

  • TI-2022-01915 The c_rehash script allows command injection CVSS 3.1CRITICAL 9.8
  • TI-2021-02645 SM2 Decryption Buffer Overflow CVSS 3.1CRITICAL 9.8
  • TI-2009-03392 The TLS protocol, and the SSL protocol 3.0 and possibly earlier, as used in Microsoft… CVSS 3.1CRITICAL 9.8
  • TI-2022-01176 The c_rehash script allows command injection CVSS 3.1CRITICAL 9.8
  • TI-2014-00154 The (1) TLS and (2) DTLS implementations in OpenSSL 1.0.1 before 1.0.1g do not properly… KEVCVSS 3.1HIGH 7.5
  • TI-2025-14107 Stack buffer overflow in CMS (Auth)EnvelopedData parsing CVSS 3.1HIGH 8.8
See all 312 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences