CVE-2026-110685: critical vulnerability in Cpanel-JSON-XS
Cpanel::JSON::XS versions before 4.80 for Perl leak the decoded arguments of a tagged value when its THAW method dies in decode_tag
Published · Updated
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28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.1epss 0.5%
Cpanel::JSON::XS versions before 4.80 for Perl leak the decoded arguments of a tagged value when its THAW method dies in decode_tag.
With allow_tags, a tagged value's class name and argument array are decoded and passed to the class's THAW method. Both are released only after THAW returns, so a THAW that dies leaves the whole decoded argument structure allocated.
Each rejected document leaks data of a size the sender chooses, so a process that catches the error and keeps running exhausts its memory.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Affected products
Cpanel-JSON-XSRelated CVEs — Cpanel-JSON-XS
In the same product, most dangerous first.
CVE-2026-110674MEDIUMCpanel::JSON::XS versions from 4.33 before 4.80 for Perl miss duplicate non-ASCII bare keys, allowing type confusion under dupkeys_as_arrayref in decode_hvEPSS 0.5%CVE-2026-110678HIGHCpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by buffering incremental input past max_size in incr_parseEPSS 0.5%CVE-2026-110676HIGHCpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by encoding exponent notation as full decimal digits under allow_bignumEPSS 0.5%CVE-2026-110673HIGHCpanel::JSON::XS versions before 4.80 for Perl allow stack exhaustion via nested tagged values under allow_tags in decode_tagEPSS 0.5%CVE-2026-110672HIGHCpanel::JSON::XS versions before 4.80 for Perl leak the decoded key of an object rejected for a duplicate key or a missing colon in decode_hvEPSS 0.5%CVE-2026-110688HIGHCpanel::JSON::XS versions from 4.51 before 4.80 for Perl allow quadratic CPU use by revalidating the remaining buffer per value in incr_parseEPSS 0.5%