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Fencer Vulns
critical 9.8

CVE-2026-116135 json

HTTP::Body versions before 1.23_01 for Perl drop mixed-case percent escapes from urlencoded form fields instead of decoding them

published 2026-10-28 12 d ago modified 2026-11-05 3 d ago also EUVD-2026-112273

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits
0
none known

Summary

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.

Patch / fix

  • libhttp-body-perl Debian 14 1.24.01-1

debian advisories DEBIAN-CVE-2026-116135

  • perl-HTTP-Body openSUSE Tumbleweed 1.240.0-1.1

opensuse advisories openSUSE-SU-2026:12346-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-116135 updated cvss 5.3

perl-http-body: HTTP::Body: Security filter bypass via improper handling of mixed-case percent-encoding

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
3 d ago

Exploit prediction

0.60% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Classification

Weakness
  • CWE-178 Improper Handling of Case Sensitivity

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.