VulnerabilityDeferred

CVE-2026-44368

Prior to 0.2.1, the mul_mod function implements multiplication via a binary expansion loop whose execution time depends on the Hamming weight of the second operand (the exponent).

MEDIUM 6.9EPSS 0.31%

Does this matter?

Lower severity and a low EPSS score (0.31%). Track it; it rarely justifies an emergency change on its own.

Description

PyQuorum is a cryptographic library for secret sharing and key management. Prior to 0.2.1, the mul_mod function implements multiplication via a binary expansion loop whose execution time depends on the Hamming weight of the second operand (the exponent). An attacker who can measure the time of secret‑sharing operations (e.g., via a remote service) could progressively recover the values of shares, ultimately leading to secret reconstruction. This vulnerability is fixed in 0.2.1.

CVSS 4.0: 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.31% probability · 24th percentile
CISA KEV: Not listed
Weakness: CWE-208
Source: security-advisories@github.com

References

https://github.com/svvqt/pyquorum/security/advisories/GHSA-7r92-3jgr-r65q

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.