CVE-2026-9487

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: 0.3%CVSS: 9.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

XML::Sig versions before 0.71 for Perl allow signature wrapping via duplicate ID.

_get_signed_xml() in lib/XML/Sig.pm, called from verify(), resolves the SignedInfo Reference/@URI to a node with the XPath expression "//*[@ID='$id']" and returns the first node of the resulting node set. A document in which two elements share that ID value is accepted: the digest and signature are checked against whichever element comes first in document order, and the duplicate is not detected.

Such a document verifies successfully while an application that resolves the same ID independently can read the second, attacker supplied element; in a SAML2 context this places the contents of an Assertion under attacker control.

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
56
EG Risk 56/100CISA SSVC

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%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
18th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 3, 2026

Last Modified

August 5, 2026

Advisory Details (2)

Auto-updated Sep 16, 2026
Patch available.
generic

Client Challenge

https://metacpan.org/release/TIMLEGGE/XML-Sig-0.71/source/Changes
generic
https://github.com/perl-net-saml2/perl-XML-Sig/commit/4976bde5245df69b8e02c6ae061acbd4891cd7f9.patch

Vendor Advisories for CVE-2026-9487(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 23× in last 7d / 144× 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 379 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-9487?
CVE-2026-9487 is a critical vulnerability published on August 3, 2026. XML::Sig versions before 0.71 for Perl allow signature wrapping via duplicate ID. getsigned_xml() in lib/XML/Sig.pm, called from verify(), resolves the SignedInfo Reference/@URI to a node with the XPath expression "//*[@ID='$id']" and returns the first node of the resulting node set. A document in…
When was CVE-2026-9487 disclosed?
CVE-2026-9487 was first published 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-2026-9487 actively exploited?
CVE-2026-9487 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (18th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-9487?
CVE-2026-9487 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-9487?
A fix for CVE-2026-9487 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-9487 are linked in the Vendor Advisories panel on this page.

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