CVE-2026-59696: Improper Validation of Specified Quantity in Input vulnerability in Erlang/OTP stdlib allows a remote attacker to degrade availability by supplying a URI whose

Improper Validation of Specified Quantity in Input vulnerability in Erlang/OTP stdlib allows a remote attacker to degrade availability by supplying a URI whose

Improper Validation of Specified Quantity in Input vulnerability in Erlang/OTP stdlib allows a remote attacker to degrade availability by supplying a URI whose port component is a very long run of digits. uri_string:get_port/1 passes the port substring to binary_to_integer/1 with no length bound, catching only error:badarg, so a syntactically valid port of up to roughly 1.26 million digits converts successfully and costs the calling process hundreds of milliseconds of arbitrary-precision arithmetic. The conversion is reached from every authority-parsing path in uri_string:parse/1, including the host, registered-name, and IPv4 and IPv6 forms. parse/1 is the documented interface for parsing URIs, so any application that parses an attacker-supplied URI is exposed without further configuration. The conversion function is documented to accept integers of any size, so bounding the input is the caller's responsibility. This issue affects OTP from OTP 21.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to stdlib from 3.5 before 6.2.2.5, from 7.0 before 7.3.0.2, and from 8.0 before 8.0.4.

Description from the National Vulnerability Database, published by 6b3ad84c-e1a6-4bf7-a703-f496b71e49db

What it means for a small business

If your business uses OTP, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.71%, higher than 53% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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