# Multiple timing variability issues in operations intended to be constant-time Advisory record · `RUSTSEC-2026-0387` - **Identifiers:** `RUSTSEC-2026-0387` - **State:** Confirmed - **Severity:** No CVSS score - **Critical:** No - **Published:** 23 Oct 2026 - **Updated:** 24 Oct 2026 - **Reviewed by a person:** No Published by OSV at 23 Oct 2026, 12:00 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `crypto-bigint` (crates.io): affected `>=0.0.0-0, <0.7.6`; fixed in `0.7.6` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > crypto-bigint versions before 0.7.6 have several operations meant to run in constant time that may execute secret-dependent branches, depending on compiler and target CPU. These include subtraction, zero counting, division, Montgomery multiplication, UintRef equality, and BoxedMontyForm::invert. An attacker able to observe timing or microarchitectural side channels could potentially learn information about secret intermediate values or invertibility, which could in some cases help recover cryptographic secrets. Upgrade to crypto-bigint 0.7.6 or later, which removes the affected branches. Written 3 Nov 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation No source has published a CVSS score for this record yet. - **CISA KEV:** Not listed. - **EPSS:** No score. ## Timeline - 31 Oct 2026, 14:24 UTC: First seen by agentprime - 31 Oct 2026, 14:24 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/RUSTSEC-2026-0387) ## Sources - [OSV: RUSTSEC-2026-0387](https://osv.dev/vulnerability/RUSTSEC-2026-0387) - - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .