CVE-2026-87737Network attack vector

Secret disclosure via scalar-dependent table lookups

Published Sep 9, 2026 · Updated Sep 9, 2026

Timing side channel in OCaml mirage-crypto-ec 0.11.3 through 2.3.0 allows remote attackers to infer secrets during NIST scalar multiplication. The lookup routine indexes precomputed tables with a secret-dependent value instead of scanning every entry, so memory-access timing varies with the scalar. Repeated timing observations can disclose cryptographic secrets through affected P-256, P-384, or P-521 ECDH and ECDSA operations.

CVSS severity5.9
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Timing side channel in OCaml mirage-crypto-ec 0.11.3 through 2.3.0 allows remote attackers to infer secrets during NIST scalar multiplication. The lookup routine indexes precomputed tables with a secret-dependent value instead of scanning every entry, so memory-access timing varies with the scalar. Repeated timing observations can disclose cryptographic secrets through affected P-256, P-384, or P-521 ECDH and ECDSA operations.

The record

CVE
CVE-2026-87737
Published
Sep 9, 2026
Updated
Sep 9, 2026
Vendor
OCaml
Product
mirage-crypto-ec
Classifications
CWE-208
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2.4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OCaml · mirage-crypto-ecversion=0 <2.4.0

Published CVSS scores

5.9OCaml Security TeamCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-208Observable Timing Discrepancy

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo