Summary
golang.org/x/text Infinite loop
Go version v0.3.3 of the x/text package fixes a vulnerability in encoding/unicode that could lead to the UTF-16 decoder entering an infinite loop, causing the program to crash or run out of memory. An attacker could provide a single byte to a UTF16 decoder instantiated with UseBOM or ExpectBOM to trigger an infinite loop if the String function on the Decoder is called, or the Decoder is passed to golang.org/x/text/transform.String.
Specific Go Packages Affected
golang.org/x/text/encoding/unicode
golang.org/x/text/transform
Impact
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
CVE-2020-14040 has a CVSS score of 6.7 (Medium). 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 (0.3.3); upgrading removes the vulnerable code path.
Affected versions
Security releases
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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Frequently Asked Questions
- What is CVE-2020-14040? CVE-2020-14040 is a medium-severity uncontrolled resource consumption vulnerability in golang.org/x/text (go), affecting versions < 0.3.3. It is fixed in 0.3.3. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- How severe is CVE-2020-14040? CVE-2020-14040 has a CVSS score of 6.7 (Medium). 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 golang.org/x/text are affected by CVE-2020-14040? golang.org/x/text (go) versions < 0.3.3 is affected.
- Is there a fix for CVE-2020-14040? Yes. CVE-2020-14040 is fixed in 0.3.3. Upgrade to this version or later.
- Is CVE-2020-14040 exploitable, and should I be worried? Whether CVE-2020-14040 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-2020-14040 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-2020-14040? Upgrade
golang.org/x/textto 0.3.3 or later.