Fulcio is a free-to-use certificate authority for issuing code signing certificates for an OpenID Connect (OIDC) identity. Prior to 1.8.3, function identity.extractIssuerURL splits (via a call to strings.Split) its argument (which is untrusted data) on periods. As a result, in the face of a malicious request with an (invalid) OIDC identity token in the payload containing many period characters, a call to extractIssuerURL incurs allocations to the tune of O(n) bytes (where n stands for the length of the function's argument), with a constant factor of about 16. This vulnerability is fixed in 1.8.3.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2025-1336 advisory.

    SSH Agent servers do not validate the size of messages when processing new identity requests, which may     cause the program to panic if the message is malformed due to an out of bounds read. (CVE-2025-47914)

    SSH servers parsing GSSAPI authentication requests do not validate the number of mechanisms specified in     the request, allowing an attacker to cause unbounded memory consumption. (CVE-2025-58181)

    crypto/x509: excluded subdomain constraint does not restrict wildcard SANs

    An excluded subdomain constraint in a certificate chain does not restrict the usage of wildcard SANs in     the leaf certificate. For example a constraint that excludes the subdomain test.example.com does not     prevent a leaf certificate from claiming the SAN *.example.com. (CVE-2025-61727)

    Within HostnameError.Error(), when constructing an error string, there is no limit to the number of hosts     that will be printed out. Furthermore, the error string is constructed by repeated string concatenation,     leading to quadratic runtime. Therefore, a certificate provided by a malicious actor can result in     excessive resource consumption. (CVE-2025-61729)

    Fulcio is a free-to-use certificate authority for issuing code signing certificates for an OpenID Connect     (OIDC) identity. Prior to 1.8.3, function identity.extractIssuerURL splits (via a call to strings.Split)     its argument (which is untrusted data) on periods. As a result, in the face of a malicious request with an     (invalid) OIDC identity token in the payload containing many period characters, a call to extractIssuerURL     incurs allocations to the tune of O(n) bytes (where n stands for the length of the function's argument),     with a constant factor of about 16. This vulnerability is fixed in 1.8.3. (CVE-2025-66506)

    Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.0.3, Function     api.ParseJSONRequest currently splits (via a call to strings.Split) an optionally-provided OID (which is     untrusted data) on periods. Similarly, function api.getContentType splits the Content-Type header (which     is also untrusted data) on an application string. As a result, in the face of a malicious request with     either an excessively long OID in the payload containing many period characters or a malformed Content-     Type header, a call to api.ParseJSONRequest or api.getContentType incurs allocations of O(n) bytes (where     n stands for the length of the function's argument). This vulnerability is fixed in 2.0.3.
    (CVE-2025-66564)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of runfinch-finch installed on the remote host is prior to 1.10.0-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2DOCKER-2025-092 advisory.

    SSH Agent servers do not validate the size of messages when processing new identity requests, which may     cause the program to panic if the message is malformed due to an out of bounds read. (CVE-2025-47914)

    SSH servers parsing GSSAPI authentication requests do not validate the number of mechanisms specified in     the request, allowing an attacker to cause unbounded memory consumption. (CVE-2025-58181)

    crypto/x509: excluded subdomain constraint does not restrict wildcard SANs

    An excluded subdomain constraint in a certificate chain does not restrict the usage of wildcard SANs in     the leaf certificate. For example a constraint that excludes the subdomain test.example.com does not     prevent a leaf certificate from claiming the SAN *.example.com. (CVE-2025-61727)

    Within HostnameError.Error(), when constructing an error string, there is no limit to the number of hosts     that will be printed out. Furthermore, the error string is constructed by repeated string concatenation,     leading to quadratic runtime. Therefore, a certificate provided by a malicious actor can result in     excessive resource consumption. (CVE-2025-61729)

    Fulcio is a free-to-use certificate authority for issuing code signing certificates for an OpenID Connect     (OIDC) identity. Prior to 1.8.3, function identity.extractIssuerURL splits (via a call to strings.Split)     its argument (which is untrusted data) on periods. As a result, in the face of a malicious request with an     (invalid) OIDC identity token in the payload containing many period characters, a call to extractIssuerURL     incurs allocations to the tune of O(n) bytes (where n stands for the length of the function's argument),     with a constant factor of about 16. This vulnerability is fixed in 1.8.3. (CVE-2025-66506)

    Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.0.3, Function     api.ParseJSONRequest currently splits (via a call to strings.Split) an optionally-provided OID (which is     untrusted data) on periods. Similarly, function api.getContentType splits the Content-Type header (which     is also untrusted data) on an application string. As a result, in the face of a malicious request with     either an excessively long OID in the payload containing many period characters or a malformed Content-     Type header, a call to api.ParseJSONRequest or api.getContentType incurs allocations of O(n) bytes (where     n stands for the length of the function's argument). This vulnerability is fixed in 2.0.3.
    (CVE-2025-66564)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Fulcio is a free-to-use certificate authority for issuing code signing certificates for an OpenID Connect     (OIDC) identity. Prior to 1.8.3, function identity.extractIssuerURL splits (via a call to strings.Split)     its argument (which is untrusted data) on periods. As a result, in the face of a malicious request with an     (invalid) OIDC identity token in the payload containing many period characters, a call to extractIssuerURL     incurs allocations to the tune of O(n) bytes (where n stands for the length of the function's argument),     with a constant factor of about 16. This vulnerability is fixed in 1.8.3. (CVE-2025-66506)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
282402	Amazon Linux 2023 : runfinch-finch (ALAS2023-2025-1336)	Nessus	Amazon Linux Local Security Checks	medium
281772	Amazon Linux 2 : runfinch-finch, --advisory ALAS2DOCKER-2025-092 (ALASDOCKER-2025-092)	Nessus	Amazon Linux Local Security Checks	medium
277692	Linux Distros Unpatched Vulnerability : CVE-2025-66506	Nessus	Misc.	high

Detections

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CVE-2025-66506

high

Tenable Plugins

medium

medium

high