Is CVE-2026-7790 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-7790 being exploited in the wild.

How severe is CVE-2026-7790?

High severity, with a CVSS score of 8.7, published 11 May 2026.

Which products and versions are affected?

Nine Nines Cowlib >= 0.6.0, < 2.16.1, 0.6.0 to 2.16.0, from 0.6.0 before 2.16.1.

Is there a fix for CVE-2026-7790?

A patch was published on 2026-05-11: Fixed in version 2.16.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-7790 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-7790?

Check whether you run Nine Nines Cowlib at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-7790: ninenines cowlib denial of service in cow_http_te

Q: Is there a fix for CVE-2026-7790?

A patch was published on 2026-05-11: Fixed in version 2.16.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-7790 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-7790?

Check whether you run Nine Nines Cowlib at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-7790 · Severity: high · CVSS 8.7 · Published 2026-05-11

A vulnerability in the cowlib library, which is used by web servers like Cowboy to handle HTTP traffic, could allow an attacker to crash the service. By sending a specially crafted web request with an extremely long header, an attacker can force the server to consume excessive processor power and memory. This results in a denial-of-service (DoS) condition, making the website or application unavailable to legitimate users.

Technologies: Nine Nines Cowlib. Vendors: Nine Nines.

Quick answers

Is CVE-2026-7790 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-7790 being exploited in the wild.
How severe is CVE-2026-7790?: High severity, with a CVSS score of 8.7, published 11 May 2026.
Which products and versions are affected?: Nine Nines Cowlib >= 0.6.0, < 2.16.1, 0.6.0 to 2.16.0, from 0.6.0 before 2.16.1.
Is there a fix for CVE-2026-7790?: A patch was published on 2026-05-11: Fixed in version 2.16.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-7790 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-7790?: Check whether you run Nine Nines Cowlib at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An uncontrolled resource consumption vulnerability exists in the cow_http_te module of cowlib due to improper validation of chunk-size hex digits in HTTP/1.1 chunked transfer-encoding. The parser accepts an unbounded number of hex digits, where each digit triggers a bignum multiplication, leading to O(N²) CPU complexity and O(N) memory usage. If the input is drip-fed (sent in small fragments), the complexity increases to O(N³) because the parser restarts the calculation on each partial read. An unauthenticated remote attacker can exploit this to cause a denial of service (DoS) through CPU exhaustion and memory amplification. The issue is fixed in version 2.16.1.

Affected products

ninenines cowlib from 0.6.0 before 2.16.1

Identifiers

CVE-2026-7790
GHSA-32p9-57cr-4x65

Timeline

2026-05-11: disclosed
2026-05-11: advisory
2026-05-11: patched: Fixed in version 2.16.1

References

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