CVE-2026-55553: Information Disclosure (CVSS 7.5)

Description

urllib is an HTTP client for Node.js that supports authentication, redirects, timeouts, and other request features. Prior to 4.9.1 and 2.44.1, urllib follows redirects through followRedirect but reuses caller-supplied options across origins. In src/HttpClient.ts, #requestInternal recursively calls this.#requestInternal(nextUrl.href, options, requestContext), causing options.headers and auth or digestAuth values to be reused when the redirect target has a different scheme, host, or port. Authorization, Cookie, Proxy-Authorization, x-api-key, x-auth-token, and x-access-token can therefore be sent to an attacker-controlled redirected origin, exposing credentials intended for the original origin and potentially allowing reuse against the original partner API or related services. No user interaction is required. This issue is fixed in versions 2.44.1 and 4.9.1.

Is your site exposed to CVE-2026-55553?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS — Exploit Prediction

0.0037

Probability of exploitation

0.31%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-200 CWE-200

CWE-201 CWE-201

CWE-522 CWE-522

References

Other References

Frequently Asked Questions

What is CVE-2026-55553? +

urllib is an HTTP client for Node.js that supports authentication, redirects, timeouts, and other request features. Prior to 4.9.1 and 2.44.1, urllib follows redirects through followRedirect but reuses caller-supplied options across origins. In src/HttpClient.ts, #requestInternal recursively calls this.#requestInternal(nextUrl.href, options, requestContext), causing options.headers and auth or digestAuth values to be reused when the redirect target has a different scheme, host, or port. Authorization, Cookie, Proxy-Authorization, x-api-key, x-auth-token, and x-access-token can therefore be sent to an attacker-controlled redirected origin, exposing credentials intended for the original origin and potentially allowing reuse against the original partner API or related services. No user interaction is required. This issue is fixed in versions 2.44.1 and 4.9.1. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-55553? +

CVE-2026-55553 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0037, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-55553? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-15625

Unauthenticated user is able to execute arbitrary SQL commands in Sparx Pro Cloud Server database in certain cases.

CVE-2026-22051

StorageGRID (formerly StorageGRID Webscale) versions prior to 11.9.0.13 and 12.0.0.6 are susceptible to a Information Disclosure vulnerability. Successful exploit could …

CVE-2026-41186

When Calico's shared debug server is enabled (disabled by default), the Calico kube-controllers and Goldmane components bind their Go pprof …

CVE-2026-54396

An information disclosure vulnerability exists in the MISP AuthKey edit functionality. When a validation error occurs during an AuthKey edit …

CVE-2026-13230

An information disclosure vulnerability was identified in TP-Link Kasa EC70 v4 and EC71 v4 in the local discovery mechanism, which …

CVE-2026-53912

Cerebrate before version 1.37 exposed credential material from self-registration requests. The self-registration workflow stored the registrant’s hashed password in the …

CVE-2026-55553