Parser hang via malformed unterminated case tag
Published Jul 9, 2026 · Updated Jul 9, 2026
Denial of service in Python Liquid before 2.2.1 allows remote authenticated users to hang template parsing via malformed case tags. The case-tag parser loops because liquid.TokenStream.eof supplies an EOF token whose kind and value do not match the sentinel checked by the parser. An attacker must be able to submit a template lacking when, else, and endcase blocks; parsing then consumes processor time indefinitely and stalls the handling process.
Summary
What happened
Denial of service in Python Liquid before 2.2.1 allows remote authenticated users to hang template parsing via malformed case tags. The case-tag parser loops because liquid.TokenStream.eof supplies an EOF token whose kind and value do not match the sentinel checked by the parser. An attacker must be able to submit a template lacking when, else, and endcase blocks; parsing then consumes processor time indefinitely and stalls the handling process.
The record
- CVE
- CVE-2026-55865
- Published
- Jul 9, 2026
- Updated
- Jul 9, 2026
- Vendor
- jg-rp
- Product
- Python Liquid
- Classifications
- CWE-835, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 9, 2026CVE publishedPublication date reported by the CVE source.
- Jul 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.2.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo