What is CVE-2016-10931?

CVE-2016-10931 is a high-severity security vulnerability in openssl (rust), affecting versions < 0.9.0. It is fixed in 0.9.0.

How severe is CVE-2016-10931?

CVE-2016-10931 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of openssl are affected by CVE-2016-10931?

openssl (rust) versions < 0.9.0 is affected.

Is there a fix for CVE-2016-10931?

Yes. CVE-2016-10931 is fixed in 0.9.0. Upgrade to this version or later.

Is CVE-2016-10931 exploitable, and should I be worried?

Whether CVE-2016-10931 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2016-10931 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

CVE-2016-10931 in openssl

Q: How severe is CVE-2016-10931?

CVE-2016-10931 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Q: Which versions of openssl are affected by CVE-2016-10931?

openssl (rust) versions < 0.9.0 is affected.

Q: Is there a fix for CVE-2016-10931?

Yes. CVE-2016-10931 is fixed in 0.9.0. Upgrade to this version or later.

Q: Is CVE-2016-10931 exploitable, and should I be worried?

Whether CVE-2016-10931 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2016-10931 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2016-10931?

Upgrade openssl to 0.9.0 or later.

Summary

Improper Certificate Validation in openssl

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).

Impact

CVE-2016-10931 has a CVSS score of 8.1 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.9.0); upgrading removes the vulnerable code path.

Affected versions

openssl (< 0.9.0)

Security releases

openssl → 0.9.0 (rust)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

Upgrade openssl to 0.9.0 or later to resolve this vulnerability.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is CVE-2016-10931? CVE-2016-10931 is a high-severity security vulnerability in openssl (rust), affecting versions < 0.9.0. It is fixed in 0.9.0.
How severe is CVE-2016-10931? CVE-2016-10931 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
Which versions of openssl are affected by CVE-2016-10931? openssl (rust) versions < 0.9.0 is affected.
Is there a fix for CVE-2016-10931? Yes. CVE-2016-10931 is fixed in 0.9.0. Upgrade to this version or later.
Is CVE-2016-10931 exploitable, and should I be worried? Whether CVE-2016-10931 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2016-10931 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2016-10931? Upgrade openssl to 0.9.0 or later.

Other vulnerabilities in openssl

CVE-IDSeverityPackage summary

CVE-2026-45784Mediumopenssl: rust-openssl: Potential out-of-bounds write in `CipherCtxRef::cipher_update_inplace` for AES-KW-PAD ciphers CVE-2026-44662Mediumopenssl: rust-openssl vulnerable to heap buffer overflow when encrypting with AES key-wrap-with-padding CVE-2026-42327Highopenssl: rust-openssl has undefined behavior in X509Ref::ocsp_responders for certificates with non-UTF-8 OCSP URLs CVE-2026-41676Highopenssl: rust-openssl: Deriver::derive and PkeyCtxRef::derive can overflow short buffers on OpenSSL 1.1.1 CVE-2026-41677Lowopenssl: rust-opennssl has an Out-of-bounds read in PEM password callback when returning an oversized length