Slab safeurl 0.1.0 toctou

Summaryinfo

A vulnerability classified as critical has been found in Slab safeurl 0.1.0. This impacts an unknown function. This manipulation causes toctou. This vulnerability is tracked as CVE-2026-77972. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in Slab safeurl 0.1.0 and classified as critical. Affected by this vulnerability is some unknown processing. The manipulation with an unknown input leads to a toctou vulnerability. The CWE definition for the vulnerability is CWE-367. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Time-of-check Time-of-use (TOCTOU) Race Condition in Slab safeurl allows an attacker who controls a hostname's DNS responses to reach internal network destinations that validation rejected. Validation returns a verdict and not the address it approved, so the HTTP clients the library ships receive the original hostname and resolve it a second time when the request is made. An attacker who controls the authoritative DNS for a name can answer the first lookup with a permitted address and the second with a blocked one, and the request then reaches a destination validation never approved. The same window opens without an attacker whenever a name legitimately resolves to different addresses across lookups, such as short record lifetimes or rotation between several addresses. This issue affects safeurl: from 0.1.0 onward.

It is possible to read the advisory at cna.erlef.org. This vulnerability is known as CVE-2026-77972 since 08/24/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Vendor

• Slab

Name

• safeurl

Version

• 0.1.0

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

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