CVE-2026-56858

MEDIUMPre-NVD 6.16.1—
EchelonGraph scoreHIGH 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 — 5 sources updated 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(high)
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
18%
KEV
Not listed

Published

August 13, 2026

Last Modified

August 14, 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(3)

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

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatgolang1-26-main-1.26.6-0.1.hum12026-08-14redhat
redhatgolang1-25-main-1.25.13-0.1.hum12026-08-14redhat

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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 26× in last 7d / 29× 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.

  1. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-20 15:07 UTCEG score recompute
  3. 2026-08-20 15:07 UTCVendor advisory
  4. 2026-08-20 15:07 UTCGHSA enrichment
  5. 2026-08-19 17:04 UTCEPSS rescore
  6. 2026-08-19 15:20 UTCVendor advisory
  7. 2026-08-19 15:20 UTCGHSA enrichment
  8. 2026-08-18 15:36 UTCEG score recompute
  9. 2026-08-18 15:36 UTCVendor advisory
  10. 2026-08-18 15:36 UTCGHSA enrichment
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-17 15:43 UTCEG score recompute
  13. 2026-08-17 15:43 UTCVendor advisory
  14. 2026-08-17 15:43 UTCGHSA enrichment
  15. 2026-08-17 13:47 UTCEPSS rescore
  16. 2026-08-16 15:59 UTCEG score recompute
  17. 2026-08-16 15:59 UTCGHSA enrichment
  18. 2026-08-16 14:56 UTCEPSS rescore
  19. 2026-08-16 02:14 UTCEPSS rescore
  20. 2026-08-15 16:16 UTCEG score recompute
  21. 2026-08-15 16:16 UTCGHSA enrichment
  22. 2026-08-15 01:30 UTCEPSS rescore
  23. 2026-08-14 16:32 UTCGHSA enrichment
  24. 2026-08-14 15:39 UTCEG score recompute▲ 6.10
  25. 2026-08-14 15:39 UTCGHSA enrichment
Show 4 more
  1. 2026-08-14 15:38 UTCMITRE cvelistV5CVSS v3 → 6.1 · severity → MEDIUM
  2. 2026-08-13 22:25 UTCNVD update
  3. 2026-08-13 22:09 UTCEG score recompute
  4. 2026-08-13 22:09 UTCMITRE cvelistV5first tracked

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 August 14, 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 81.6% 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

Explore the affected products and dependency analysis for CVE-2026-56858

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