Go net/url quadratic path resolution DoS before 1.27.0-rc.3
CVE-2026-56860 Published on August 13, 2026
Avoid quadratic complexity in resolvePath in net/url
Previously, resolving relative paths containing parent directory ('..') segments performed string conversions and buffer rewrites on each step, resulting in quadratic time complexity and high memory allocation overhead. Now, path resolution operates on a byte buffer using index-based backtracking for '..' segments, eliminating the quadratic time complexity and significantly reducing memory allocations.
Vulnerability Analysis
CVE-2026-56860 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
Inefficient Algorithmic Complexity
An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.
Products Associated with CVE-2026-56860
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Affected Versions
Go standard library net/url:- Before 1.25.13 is affected.
- Version 1.26.0-0 and below 1.26.6 is affected.
- Version 1.27.0-0 and below 1.27.0-rc.3 is affected.