Vulnerability · Published Oct 28, 2026 · Assigned by CPANSec
CVE-2026-116135HTTP::Body versions before 1.23_01 for Perl drop mixed-case percent escapes from urlencoded form fields instead of decoding them
Critical 9.8
In plain English
A critical-severity security flaw in HTTP-Body. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
HTTP::Body versions before 1.23_01 for Perl drop mixed-case percent escapes from urlencoded form fields instead of decoding them. The decode table holds only the all-lowercase and all-uppercase spelling of each hex pair, while the escape pattern matches either case. An escape such as %aB finds no entry and is replaced with nothing, joining the bytes on either side. Hex digits in percent escapes are case-insensitive, and conforming decoders return the byte. A remote attacker can send a field name or value that a conforming decoder in front of the application reads differently, so that pass%aBword reaches the application as password.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libhttp-body-perl | no fix listed | DEBIAN-CVE-2026-116135 |
| Debian:13 | libhttp-body-perl | no fix listed | DEBIAN-CVE-2026-116135 |
| Debian:14 | libhttp-body-perl | 1.24.01-1 | DEBIAN-CVE-2026-116135 |
| Ubuntu:22.04:LTS | libhttp-body-perl | no fix listed | UBUNTU-CVE-2026-116135 |
| Ubuntu:24.04:LTS | libhttp-body-perl | no fix listed | UBUNTU-CVE-2026-116135 |
| Ubuntu:26.04:LTS | libhttp-body-perl | no fix listed | UBUNTU-CVE-2026-116135 |
| Ubuntu:26.10 | libhttp-body-perl | no fix listed | UBUNTU-CVE-2026-116135 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| HTTP-Body | 0 – before 1.23_01 |
Weakness: CWE-178 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H