CVE-2026-9390
XPath injection in Perl XML::Sig can bypass XML signature verification.
Is CVE-2026-9390 being exploited?
Not confirmed. CVE-2026-9390 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.29% probability of exploitation in the next 30 days.
How severe is CVE-2026-9390?
CVE-2026-9390 is rated Critical with a CVSS score of 9.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-9390?
Yes. A fix has been recorded for CVE-2026-9390. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-9390 affect?
CVE-2026-9390 affects Perl XML::Sig < 0.71, Perl applications performing XML signature verification (SAML/SOAP handlers), Any service using XML::Sig for digest verification. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-9390?
Upgrade XML::Sig to >=0.71 or apply vendor patch; escape/validate ID URIs.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
XPath injection in ID lookup lets attacker control which node is hashed, enabling XML signature verification bypass and acceptance of forged signed XML.
Immediate action required
- affected< 0.71
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.