Memory exhaustion in Cpanel::JSON::XS incremental parsing
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-770.
Summary
Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by buffering incremental input past max_size in incr_parse. The parser appends each chunk to its buffer and compares max_size with its progress instead of the buffer length, so a chunk starting with a NUL byte or a call in void context lets the buffer grow without limit (CWE-770). A peer streaming data to an incr_parse consumer can exhaust process memory regardless of max_size.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
Cpanel::JSON::XS versions before 4.80 for Perl allow memory exhaustion by buffering incremental input past max_size in incr_parse. The parser appends each chunk to its buffer. In scalar or list context, it compares max_size with how far it has progressed, not with the buffer length. A chunk that starts with a NUL byte stops the parser before it progresses, and a call in void context skips the check, so the buffer grows without limit. A peer streaming data to an incr_parse consumer can exhaust process memory regardless of max_size.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Cpanel-JSON-XS | before 4.80 | 4.80 | Patch available | CNA |
- Cpanel-JSON-XS Vendor— Affected before 4.80 Fixed in 4.80 Patch available CNA
Remediation
Upgrade Cpanel-JSON-XS to version 4.80 or later, which is the fixed version.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA Cpanel-JSON-XS Fixed in 4.80
Vendor assessments
Timeline
- 2026-10-20 Threatist record created from CVE-2026-110678
- 2026-10-20 Alias added: GHSA-94qg-48qm-9798
- 2026-10-20 Affected versions changed · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-10-29 CVSS score added · CISA ADP
- 2026-10-29 CISA SSVC decision points changed
References
Sources
- CVE-2026-110678 · CVE Program
- CVE-2026-110678 · NVD
- FIRST EPSS
- GHSA-94qg-48qm-9798 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-110678 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences