Skip to content
Fencer Vulns
critical 9.1

CVE-2026-9390 json

XML::Sig versions before 0.71 for Perl allow XPath injection in ID lookup

published 2026-08-03 3 mo ago modified 2026-10-23 16 d ago also EUVD-2026-52269

cvss
9.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

XML::Sig versions before 0.71 for Perl allow XPath injection in ID lookup.

verify() and _get_signed_xml() in lib/XML/Sig.pm build XPath expressions by concatenating the SignedInfo/Reference/@URI value read from the document being verified. The value is neither escaped nor checked against the NCName grammar that XML requires of an ID, so a URI containing a single quote closes the string literal in the generated expression and appends arbitrary XPath operators.

A crafted URI can make the lookup match elements the reference does not name, or every element in the document, so which node is selected for digest verification is decided by the injected expression rather than by the reference.

Patch / fix

  • TIMLEGGE XML::Sig 0.71

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
3 mo ago

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CNA 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

  • TIMLEGGE XML::Sig

Classification

Weakness
  • CWE-643 Improper Neutralization of Data within XPath Expressions
  • CWE-1287 Improper Validation of Specified Type of Input

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.