Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
🦀
🦀 crates.io
Not in CISA KEV
HIGH severity

CVE-2016-10931 — openssl

HIGH

CVE-2016-10931 is a high-severity (CVSS 8.1) CWE-295 vulnerability in openssl. A fix is available for openssl — see the affected versions and patch details below.

Improper Certificate Validation in openssl

Also known asGHSA-34p9-f4q3-c4r7RUSTSEC-2016-0001
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.7%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs53th percentile — riskier than 53% of all scored CVEsHighest risk
0.00%0.41%0.83%1.24%0.2%0.7%Apr 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2016-10931 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected
🦀openssl

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.

Description

All versions of rust-openssl prior to 0.9.0 contained numerous insecure defaults including off-by-default certificate verification and no API to perform hostname verification. Unless configured correctly by a developer, these defaults could allow an attacker to perform man-in-the-middle attacks. The problem was addressed in newer versions by enabling certificate verification by default and exposing APIs to perform hostname verification. Use the SslConnector and SslAcceptor types to take advantage of these new features (as opposed to the lower-level SslContext type).

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🦀crates.ioopensslall versions0.9.0cargo update -p openssl --precise 0.9.0

Affected Products

1 product · 1 configurations
Application
rust-opensslrust-openssl_project
< 0.9.0
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openssl, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update openssl to 0.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-10931 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

All versions of rust-openssl prior to 0.9.0 contained numerous insecure defaults including off-by-default certificate verification and no API to perform hostname verification. Unless configured correctly by a developer, these defaults could allow an attacker to perform man-in-the-middle attacks. The problem was addressed in newer versions by enabling certificate verification by default and exposing APIs to perform hostname verification. Use the SslConnector and SslAcceptor types to take advantage of these new features (as opposed to the lower-level SslContext type).
O3 Security · Impact-Aware SCA

Is CVE-2016-10931 in your dependencies?

Find it across crates.io, including transitive dependencies.

Scan my dependencies How O3 SCA works
CVE-2016-10931: openssl — Fixed in 0.9.0