CVE-2026-9390

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-03. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
56(Track)
EG Risk 56/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity91% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

August 3, 2026

Last Modified

August 5, 2026

Advisory Details (3)

Auto-updated Sep 16, 2026
No patch confirmed yet.
generic

Changes - metacpan.org

https://metacpan.org/release/TIMLEGGE/XML-Sig-0.71/changes
generic
https://github.com/perl-net-saml2/perl-XML-Sig/commit/a85aad21aa767ac1c158bbfc19447683941ab376.patch
generic
https://github.com/perl-net-saml2/perl-XML-Sig/commit/69ad2b421118fadd33d57f50b110b8d161e8fef5.patch

Vendor Advisories for CVE-2026-9390(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 42× in last 7d / 170× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 302 total refreshes for this CVE.

  1. 2026-09-19 04:22 UTCGHSA enrichment
  2. 2026-09-18 23:59 UTCEG score recompute
  3. 2026-09-18 23:59 UTCGHSA enrichment
  4. 2026-09-18 19:28 UTCEPSS rescore
  5. 2026-09-18 19:17 UTCGHSA enrichment
  6. 2026-09-18 14:50 UTCGHSA enrichment
  7. 2026-09-18 09:56 UTCGHSA enrichment
  8. 2026-09-18 05:34 UTCGHSA enrichment
  9. 2026-09-18 01:11 UTCEG score recompute
  10. 2026-09-18 01:11 UTCGHSA enrichment
  11. 2026-09-17 19:32 UTCEPSS rescore
  12. 2026-09-17 10:03 UTCGHSA enrichment
  13. 2026-09-17 05:40 UTCGHSA enrichment
  14. 2026-09-17 01:15 UTCEG score recompute
  15. 2026-09-17 01:15 UTCGHSA enrichment
  16. 2026-09-16 14:09 UTCEPSS rescore
  17. 2026-09-16 11:18 UTCGHSA enrichment
  18. 2026-09-16 05:19 UTCEG score recompute
  19. 2026-09-16 05:19 UTCGHSA enrichment
  20. 2026-09-16 05:15 UTCEPSS rescore
  21. 2026-09-15 16:57 UTCGHSA enrichment
  22. 2026-09-15 07:01 UTCEG score recompute
  23. 2026-09-15 07:01 UTCGHSA enrichment
  24. 2026-09-15 03:12 UTCEPSS rescore
  25. 2026-09-15 01:57 UTCGHSA enrichment
Show 75 more
  1. 2026-09-14 14:07 UTCGHSA enrichment
  2. 2026-09-14 09:26 UTCGHSA enrichment
  3. 2026-09-14 05:03 UTCGHSA enrichment
  4. 2026-09-14 00:41 UTCGHSA enrichment
  5. 2026-09-13 20:18 UTCEG score recompute
  6. 2026-09-13 20:18 UTCGHSA enrichment
  7. 2026-09-13 16:48 UTCEPSS rescore
  8. 2026-09-13 15:55 UTCGHSA enrichment
  9. 2026-09-13 11:32 UTCGHSA enrichment
  10. 2026-09-13 07:09 UTCGHSA enrichment
  11. 2026-09-13 02:47 UTCGHSA enrichment
  12. 2026-09-12 22:24 UTCGHSA enrichment
  13. 2026-09-12 17:59 UTCEG score recompute
  14. 2026-09-12 17:59 UTCGHSA enrichment
  15. 2026-09-12 15:02 UTCEPSS rescore
  16. 2026-09-12 13:36 UTCGHSA enrichment
  17. 2026-09-12 09:14 UTCGHSA enrichment
  18. 2026-09-12 04:51 UTCGHSA enrichment
  19. 2026-09-12 00:28 UTCGHSA enrichment
  20. 2026-09-11 19:19 UTCGHSA enrichment
  21. 2026-09-11 14:54 UTCEG score recompute
  22. 2026-09-11 14:54 UTCGHSA enrichment
  23. 2026-09-11 14:53 UTCEPSS rescore
  24. 2026-09-11 09:38 UTCEPSS rescore
  25. 2026-09-11 07:29 UTCGHSA enrichment
  26. 2026-09-11 03:07 UTCGHSA enrichment
  27. 2026-09-10 22:43 UTCGHSA enrichment
  28. 2026-09-10 18:20 UTCGHSA enrichment
  29. 2026-09-10 12:51 UTCEG score recompute
  30. 2026-09-10 12:51 UTCGHSA enrichment
  31. 2026-09-10 09:35 UTCEPSS rescore
  32. 2026-09-10 07:35 UTCGHSA enrichment
  33. 2026-09-10 03:12 UTCGHSA enrichment
  34. 2026-09-09 19:39 UTCGHSA enrichment
  35. 2026-09-09 11:09 UTCGHSA enrichment
  36. 2026-09-09 06:47 UTCEG score recompute
  37. 2026-09-09 06:47 UTCGHSA enrichment
  38. 2026-09-08 22:01 UTCEPSS rescore
  39. 2026-09-08 03:45 UTCGHSA enrichment
  40. 2026-09-07 23:20 UTCGHSA enrichment
  41. 2026-09-07 18:57 UTCEG score recompute
  42. 2026-09-07 18:57 UTCGHSA enrichment
  43. 2026-09-06 21:17 UTCGHSA enrichment
  44. 2026-09-06 16:49 UTCEG score recompute
  45. 2026-09-06 16:49 UTCGHSA enrichment
  46. 2026-09-06 13:48 UTCEPSS rescore
  47. 2026-09-06 12:26 UTCGHSA enrichment
  48. 2026-09-06 07:49 UTCGHSA enrichment
  49. 2026-09-06 03:26 UTCGHSA enrichment
  50. 2026-09-05 23:03 UTCGHSA enrichment
  51. 2026-09-05 18:40 UTCEG score recompute
  52. 2026-09-05 18:40 UTCGHSA enrichment
  53. 2026-09-05 15:31 UTCEPSS rescore
  54. 2026-09-05 08:49 UTCGHSA enrichment
  55. 2026-09-05 04:26 UTCGHSA enrichment
  56. 2026-09-04 14:40 UTCEG score recompute
  57. 2026-09-04 14:40 UTCGHSA enrichment
  58. 2026-09-04 10:17 UTCEG score recompute
  59. 2026-09-04 10:17 UTCGHSA enrichment
  60. 2026-09-04 05:07 UTCEPSS rescore
  61. 2026-09-04 03:27 UTCGHSA enrichment
  62. 2026-09-03 17:51 UTCGHSA enrichment
  63. 2026-09-03 08:55 UTCEG score recompute
  64. 2026-09-03 08:54 UTCGHSA enrichment
  65. 2026-09-02 14:12 UTCEPSS rescore
  66. 2026-09-02 07:50 UTCGHSA enrichment
  67. 2026-09-01 22:17 UTCEG score recompute
  68. 2026-09-01 22:17 UTCGHSA enrichment
  69. 2026-09-01 13:54 UTCEPSS rescore
  70. 2026-09-01 07:22 UTCEG score recompute
  71. 2026-09-01 07:22 UTCGHSA enrichment
  72. 2026-09-01 04:40 UTCEPSS rescore
  73. 2026-08-31 23:12 UTCGHSA enrichment
  74. 2026-08-31 04:46 UTCGHSA enrichment
  75. 2026-08-31 00:23 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-9390?
CVE-2026-9390 is a critical vulnerability published on August 3, 2026. XML::Sig versions before 0.71 for Perl allow XPath injection in ID lookup. verify() and getsigned_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…
When was CVE-2026-9390 disclosed?
CVE-2026-9390 was first published in the National Vulnerability Database on August 3, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-9390 actively exploited?
CVE-2026-9390 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 78.3% of all scored CVEs.
What is the CVSS score of CVE-2026-9390?
CVE-2026-9390 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-9390?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-9390, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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