Quick answers
- Is CVE-2026-121006 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-121006 being exploited in the wild.
- How severe is CVE-2026-121006?
- Informational severity, published 6 November 2026.
- Which products and versions are affected?
- Perl HTTP::Body before 1.24_02.
- Is there a fix for CVE-2026-121006?
- Yes: fixed in HTTP::Body 1.24_02. Until then: Upgrade to HTTP::Body version 1.24_02 or later. The fix enforces limits on trailer size (32,768 bytes) and the number of header lines (100) in chunked bodies to prevent quadratic-time parsing. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-121006 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-121006?
- Check whether you run Perl HTTP::Body at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: HTTP::Body 1.24_02
Upgrade to HTTP::Body version 1.24_02 or later. The fix enforces limits on trailer size (32,768 bytes) and the number of header lines (100) in chunked bodies to prevent quadratic-time parsing.
Technical details
HTTP::Body before version 1.24_02 parses chunked transfer encoding trailers using HTTP::Headers, which has quadratic time complexity when processing multiple headers with the same field name. An attacker can send a single HTTP request with a chunked body whose trailer contains thousands of duplicate header lines (e.g., 16 KiB of "a:" lines), causing the parser to consume several seconds of CPU time per request. Version 1.24_02 and later limit trailer size to 32,768 bytes and 100 header lines to mitigate this attack.
Affected products
- Perl HTTP::Body before 1.24_02
Timeline
- 2026-11-06: disclosed
- 2026-11-03: patched