A chunk-size line is matched as a run of hex digits, then .* and a CRLF. A run followed by a bare LF and then a CRLF can never match, and the engine retries the match once for each digit, so the time taken grows with the square of the run length. Nothing limits the length of the run, which can span several reads.
A remote attacker can occupy a worker for about a minute of CPU time with one 128 KiB request, before the application is called.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
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| unaffected |
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| Vendor | Product | Confidence | Versions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Kazuho | Starlet | 90% |
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Vendor Solution
Upgrade to Starlet 0.33 or later.
Tracking
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No advisories yet.
Fri, 30 Oct 2026 15:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Kazuho
Kazuho starlet |
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| Vendors & Products |
Kazuho
Kazuho starlet |
Fri, 30 Oct 2026 13:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Starlet versions from 0.20 before 0.33 for Perl allow CPU exhaustion via regular expression backtracking when decoding chunked request bodies. A chunk-size line is matched as a run of hex digits, then .* and a CRLF. A run followed by a bare LF and then a CRLF can never match, and the engine retries the match once for each digit, so the time taken grows with the square of the run length. Nothing limits the length of the run, which can span several reads. A remote attacker can occupy a worker for about a minute of CPU time with one 128 KiB request, before the application is called. | |
| Title | Starlet versions from 0.20 before 0.33 for Perl allow CPU exhaustion via regular expression backtracking when decoding chunked request bodies | |
| Weaknesses | CWE-1333 | |
| References |
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Subscriptions
No data.
MITRE
Status: PUBLISHED
Assigner: CPANSec
Published:
Updated: 2026-10-30T12:45:39.814Z
Reserved: 2026-10-23T17:41:34.521Z
Link: CVE-2026-115866
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-30T13:18:31.070
Modified: 2026-10-30T13:18:31.070
Link: CVE-2026-115866
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-10-30T14:45:14Z
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CWE-1333
Inefficient Regular Expression Complexity