OSEC-2026-17 (CVE-2026-87737)
Vulnerability from osv_ocaml – Published: 2026-08-17 09:45 – Updated: 2026-09-10 09:45 – Source websiteThe scalar multiplication includes pre-computed tables for speedup (introduced in mirage-crypto-ec 0.11.3). The lookup algorithm for these tables performs secret-dependent reads instead of scanning the entire table.
Solution
Instead of using the index n - 1, where n is secret-dependent, use i - 1, as done in the Go reference implementation. If n is 0, there is a out-of-bounds read before the patch.
Timeline
- 2026-08-12: report by Eric Ebinger to security@ocaml.org
- 2026-08-17: release of mirage-crypto-ec 2.4.0 and this advisory
{
"affected": [
{
"ecosystem_specific": {
"affected_bindings": [
"Mirage_crypto_ec.P256.Dh.share",
"Mirage_crypto_ec.P256.Dsa.generate",
"Mirage_crypto_ec.P256.Dsa.sign",
"Mirage_crypto_ec.P256.Dsa.pub_of_priv",
"Mirage_crypto_ec.P384.Dh.share",
"Mirage_crypto_ec.P384.Dsa.generate",
"Mirage_crypto_ec.P384.Dsa.sign",
"Mirage_crypto_ec.P384.Dsa.pub_of_priv",
"Mirage_crypto_ec.P521.Dh.share",
"Mirage_crypto_ec.P521.Dsa.generate",
"Mirage_crypto_ec.P521.Dsa.sign",
"Mirage_crypto_ec.P521.Dsa.pub_of_priv"
],
"opam_constraint": "mirage-crypto-ec {\u003e= \"0.11.3\" \u0026 \u003c \"2.4.0\"}"
},
"package": {
"ecosystem": "opam",
"name": "mirage-crypto-ec",
"purl": "pkg:opam/mirage-crypto-ec"
},
"ranges": [
{
"events": [
{
"introduced": "0.11.3"
},
{
"fixed": "2.4.0"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"0.11.3",
"1.0.0",
"1.1.0",
"1.2.0",
"2.0.0",
"2.0.1",
"2.0.2",
"2.0.3",
"2.1.0",
"2.2.0",
"2.3.0"
]
},
{
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1a61aeee7f593ec067612df1739ec905eab0450f"
}
],
"repo": "https://github.com/mirage/mirage-crypto",
"type": "GIT"
}
]
}
],
"aliases": [
"CVE-2026-87737"
],
"credits": [
{
"name": "Eric Ebinger",
"type": "REPORTER"
},
{
"name": "Hannes Mehnert",
"type": "COORDINATOR"
},
{
"name": "Virgile Robles",
"type": "REMEDIATION_REVIEWER"
},
{
"name": "Eric Ebinger",
"type": "REMEDIATION_DEVELOPER"
}
],
"database_specific": {
"cwe": [
"CWE-208"
],
"human_link": "https://github.com/ocaml/security-advisories/tree/main/advisories/2026/OSEC-2026-17.md",
"osv": "https://github.com/ocaml/security-advisories/tree/generated-osv/2026/OSEC-2026-17.json"
},
"details": "The scalar multiplication includes pre-computed tables for speedup (introduced in mirage-crypto-ec 0.11.3). The lookup algorithm for these tables performs secret-dependent reads instead of scanning the entire table.\n\n## Solution\n\nInstead of using the index `n - 1`, where `n` is secret-dependent, use `i - 1`, as done in the Go reference implementation. If `n` is 0, there is a out-of-bounds read before the patch.\n\n## Timeline\n- 2026-08-12: report by Eric Ebinger to security@ocaml.org\n- 2026-08-17: release of mirage-crypto-ec 2.4.0 and this advisory",
"id": "OSEC-2026-17",
"modified": "2026-09-10T09:45:00Z",
"published": "2026-08-17T09:45:00Z",
"references": [],
"schema_version": "1.7.4",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
"type": "CVSS_V3"
}
],
"summary": "Timing leak in NIST elliptic curves scalar multiplication"
}
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