VulnerabilityPublished 19 Oct 2026Updated 28 Oct 2026

CVE-2026-110688: Libcpanel json xs perl · Cpanel::JSON::XS versions from 4.51 before 4.80 for Perl allow quadratic CPU

Affects libcpanel-json-xs-perlSource GCVE Database

Authoritative record:CVE-2026-110688· Medium

Not known to be exploited.

Data as of 28 Oct 2026, 22:31 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.10libcpanel-json-xs-perl`pkg:deb/ubuntu/libcpanel-json-xs-perl?arch=source&distro=stonking`Other threats	Affected =4.40-1 =4.42-1 =4.42-1build1	Fixed in–
Ubuntu 26.04 LTSlibcpanel-json-xs-perl`pkg:deb/ubuntu/libcpanel-json-xs-perl?arch=source&distro=resolute`Other threats	Affected =4.39-2 =4.40-1	Fixed in–
Ubuntu 24.04 LTSlibcpanel-json-xs-perl`pkg:deb/ubuntu/libcpanel-json-xs-perl?arch=source&distro=noble`Other threats	Affected 4.37-1 – 4.37-1ubuntu0.1 5 affected builds	Fixed in–
Ubuntu 22.04 LTSlibcpanel-json-xs-perl`pkg:deb/ubuntu/libcpanel-json-xs-perl?arch=source&distro=jammy`Other threats	Affected 4.25-1build1 – 4.27-1ubuntu0.2 6 affected builds	Fixed in–
Ubuntu 20.04 LTSlibcpanel-json-xs-perl`pkg:deb/ubuntu/libcpanel-json-xs-perl?arch=source&distro=focal`Other threats	Affected 4.12-1 – 4.19-1ubuntu0.1 8 affected builds	Fixed in–
Ubuntu 18.04 LTSlibcpanel-json-xs-perl`pkg:deb/ubuntu/libcpanel-json-xs-perl?arch=source&distro=bionic`Other threats	Affected =3.0225-1build1 =3.0239-1	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

Cpanel::JSON::XS versions from 4.51 before 4.80 for Perl allow quadratic CPU use by revalidating the remaining buffer per value in incr_parse. At the first non-ASCII byte in a string, the decoder validates UTF-8 from there to the end of its input. incr_parse decodes each buffered value with a fresh decoder, so every value revalidates the rest of the buffer, and doubling the input quadruples the work. A peer that sends about a megabyte of ordinary non-ASCII JSON in one read ties up the process for seconds of CPU time.

References

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