Description
HTTP::Body versions before 1.23_01 for Perl allow CPU exhaustion via quadratic regex backtracking when parsing chunked request bodies. In chunked mode, used when no content length is given, add() matches each chunk-size line with `/^([\da-fA-F]+).*\x0D\x0A/`. On a line of hex digits whose first LF has no CR before it, the digits and `.*` backtrack against each other, so a single add() takes time quadratic in the line's length. Nothing limits how long the line can be. A remote attacker can exhaust CPU in applications that pass chunked request bodies to HTTP::Body.
References2
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 33 · as of 7 November 2026
- CWE
- CWE-1333
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.