CVE-2026-56858

MEDIUMPre-NVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

Score 6.1 from GitHub Security Advisory published 2026-08-14. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 6.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — Patch released this week
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: None knownExposed: 0

A fix is available — apply it.

Previously, pathological inputs could close an unescaped '/' early, allowing for attack-controlled data to inject arbitrary content, potentially leading to XSS.

CVSS v3
6.1
EG Score
6.1(medium)
EG Risk
28(Track)
EG Risk 28/100SSVC: 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
Severity61% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
24%
KEV
Not listed

Published

August 13, 2026

Last Modified

September 3, 2026

Advisory Details (4)

Auto-updated Aug 14, 2026
No patch confirmed yet.
generic

GO-2026-6091 - Go Packages

https://pkg.go.dev/vuln/GO-2026-6091
generic
https://groups.google.com/g/golang-announce/c/94pEornpRlI
generic
https://go.dev/cl/807100
generic

html/template: potential XSS caused by wrong JavaScript regexp context tracking after top-level `{` · Issue #80435 · golang/go · GitHub

https://go.dev/issue/80435

Vendor Advisories for CVE-2026-56858(20)

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

Patch Availability(30)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatosbuild-composer-0:75-10.el8_82026-09-17redhat
redhatopentelemetry-collector-0:0.152.1-2.el9_42026-09-17redhat
redhatflightctl-0:1.2.1-1.el92026-09-16redhat
redhatopentelemetry-collector-0:0.152.1-2.el10_02026-09-16redhat
redhatflightctl-0:1.1.4-1.el9em2026-09-16redhat
redhatcryostat/cryostat-storage-rhel9:4.2.0-222026-09-16redhat
redhatopentelemetry-collector-0:0.152.1-2.el9_62026-09-16redhat
redhatopenshift-0:4.20.0-202609041738.p2.g4012064.assembly.stream.el82026-09-15redhat
redhatopenshift-0:4.22.0-202609021800.p2.g19365a0.assembly.stream.el82026-09-15redhat
redhatgrafana-0:10.2.6-26.el10_02026-09-15redhat
redhatgrafana-0:10.2.6-23.el9_62026-09-15redhat
redhatdelve-0:1.26.1-1.el9_4.12026-09-14redhat
redhatgrafana-pcp-0:5.1.1-15.el9_6.12026-09-14redhat
redhatgrafana-pcp-0:5.1.1-5.el9_2.22026-09-14redhat
redhatdelve-0:1.26.1-1.el9_6.12026-09-14redhat
redhatgrafana-pcp-0:5.1.1-9.el9_42026-09-14redhat
redhatdelve-0:1.26.1-1.el9_2.12026-09-14redhat
redhatgrafana-pcp-0:5.3.0-1.el10_0.12026-09-11redhat
redhatosbuild-composer-0:134.1-12.el10_02026-09-10redhat
redhatquay/quay-rhel8:17885943762026-09-10redhat
redhatopenshift-logging/eventrouter-rhel9:17883757962026-09-10redhat
redhatexternal-secrets-operator/external-secrets-rhel9:17889639292026-09-10redhat
redhatosbuild-composer-0:101.5-2.el8_102026-09-09redhat
redhatdelve-0:1.26.1-2.el10_02026-09-09redhat
redhatignition-0:2.17.0-2.el9_4.22026-09-09redhat
redhatosbuild-composer-0:165.1-3.el10_2.22026-09-09redhat
redhatimage-builder-0:52.1-1.el9_8.22026-09-09redhat
redhatquay/quay-rhel8:17885618412026-09-09redhat
redhatoadp/oadp-velero-rhel9:17888604612026-09-09redhat
redhatbuildah-2:1.43.1-6.el10_22026-09-08redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(6 across 4 ecosystems)
Debian:14(3)
PackageVulnerable rangeFixed inDependents
golang-1.251.25.0-1 ... 1.25.9-1 (20 versions)——
golang-1.261.26.0-1 ... 1.26~rc3-2 (16 versions)1.26.6-1—
golang-1.271.27~rc1-1, 1.27~rc2-11.27~rc3-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
golang-1.191.19.10-1 ... 1.19.9-1 (12 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
golang-1.241.24.12-1 ... 1.24.9-1 (10 versions)——
Go(1)
PackageVulnerable rangeFixed inDependents
stdlib—1.27.0-rc.3—

Weakness Classification(1)

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

All Vendor Advisories

(25)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 26× in last 7d / 110× 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 135 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-56858?
CVE-2026-56858 is a medium vulnerability published on August 13, 2026. Previously, pathological inputs could close an unescaped '/' early, allowing for attack-controlled data to inject arbitrary content, potentially leading to XSS.
When was CVE-2026-56858 disclosed?
CVE-2026-56858 was first published in the National Vulnerability Database on August 13, 2026, with the most recent update on September 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56858 actively exploited?
CVE-2026-56858 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 76.0% of all scored CVEs.
What is the CVSS score of CVE-2026-56858?
CVE-2026-56858 has a CVSS v3.1 base score of 6.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-56858?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56858, 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.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-56858

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