What is CVE-2026-55406?

CVE-2026-55406 is a medium-severity use after free vulnerability in buffa (rust), affecting versions < 0.7.0. It is fixed in 0.7.0. Memory is accessed after it has been freed, leading to undefined behavior in native code.

Which versions of buffa are affected by CVE-2026-55406?

buffa (rust) versions < 0.7.0 is affected.

Is there a fix for CVE-2026-55406?

Yes. CVE-2026-55406 is fixed in 0.7.0. Upgrade to this version or later.

Is CVE-2026-55406 exploitable, and should I be worried?

Whether CVE-2026-55406 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-2026-55406 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-2026-55406 in buffa

Q: Which versions of buffa are affected by CVE-2026-55406?

buffa (rust) versions < 0.7.0 is affected.

Q: Is there a fix for CVE-2026-55406?

Yes. CVE-2026-55406 is fixed in 0.7.0. Upgrade to this version or later.

Q: Is CVE-2026-55406 exploitable, and should I be worried?

Whether CVE-2026-55406 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-2026-55406 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-2026-55406?

Upgrade buffa to 0.7.0 or later.

Summary

Buffa has a Use-After-Free in OwnedView via Unsound 'static Lifetime Promotion in Deref

A soundness bug in buffa's OwnedView<V> allowed safe Rust code to trigger a use-after-free. The OwnedView::decode constructor transmuted a borrowed slice to &'static [u8], and the Deref implementation exposed the promoted 'static lifetime on borrowed view fields (such as &'static str and &'static [u8]) to callers. Because these references appeared to be 'static, the borrow checker permitted them to outlive the OwnedView; once the OwnedView was dropped and its backing buffer freed, those references became dangling, enabling memory corruption, information disclosure of freed heap contents, and cross-thread misuse, all without any unsafe code in the calling application. Users are advised to update to the latest patched version of buffa.

Thank you to hackerone.com/suul for reporting this issue.

Impact

Memory is accessed after it has been freed, leading to undefined behavior in native code. Typical impact: memory corruption, crash, or potential code execution.

Affected versions

buffa (< 0.7.0)

Security releases

buffa → 0.7.0 (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 buffa to 0.7.0 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-2026-55406? CVE-2026-55406 is a medium-severity use after free vulnerability in buffa (rust), affecting versions < 0.7.0. It is fixed in 0.7.0. Memory is accessed after it has been freed, leading to undefined behavior in native code.
Which versions of buffa are affected by CVE-2026-55406? buffa (rust) versions < 0.7.0 is affected.
Is there a fix for CVE-2026-55406? Yes. CVE-2026-55406 is fixed in 0.7.0. Upgrade to this version or later.
Is CVE-2026-55406 exploitable, and should I be worried? Whether CVE-2026-55406 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-2026-55406 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-2026-55406? Upgrade buffa to 0.7.0 or later.