Quick answers
- Is CVE-2026-110688 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-110688 being exploited in the wild.
- How severe is CVE-2026-110688?
- Informational severity, published 19 October 2026.
- Which products and versions are affected?
- Cpanel::JSON::XS 4.51 to 4.79.
- Is there a fix for CVE-2026-110688?
- Yes: fixed in 4.80. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-110688 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-110688?
- Check whether you run Cpanel::JSON::XS 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.
How to fix
- Fixed in: 4.80
Technical details
The incr_parse function revalidates UTF-8 encoding from the first non-ASCII byte to the end of the entire input buffer for each JSON value decoded, rather than just the decoded portion. When buffered input contains multiple values with non-ASCII text, each subsequent value revalidates the entire remainder of the buffer, resulting in quadratic CPU consumption. The vulnerability requires the attacker to send JSON over the network, and affects versions 4.51 through 4.79.
Affected products
- Cpanel::JSON::XS 4.51 to 4.79
Timeline
- 2026-10-19: disclosed