Vulnerability · CVE-2026-56858
Fix Javascript regexp context tracking in html/template
Published Aug 13, 2026 · catalog updated Oct 15, 2026 · Fix Javascript regexp context
Check if you run it
No confirmed exploitation is on record for CVE-2026-56858. EPSS is 0.31%. Act only if a listed version of Fix Javascript regexp context is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (Fix Javascript regexp context).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Unknown—
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.31%
- Remediation
- Not established
- Affected products
- Go stdlib
Previously, pathological inputs could close an unescaped '/' early, allowing for attack-controlled data to inject arbitrary content, potentially leading to XSS.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- Go stdlib0 → 1.25.13
How to fix CVE-2026-56858
Recommended remediation
No required-action text, fix commit, or clear fixed-version range is stored yet.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-56858. EPSS is 0.31%. Act only if a listed version of Fix Javascript regexp context is installed.
Which versions are affected?
Compare what you have installed with 0 → 1.25.13. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.31%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Aug 13, 2026 · Catalog
Detected
Previously, pathological inputs could close an unescaped '/' early, allowing for attack-controlled data to inject arbitrary content, potentially leading to XSS.
Oct 10, 2026 · Catalog
Fix available
Go stdlib 0 → 1.25.13
Oct 10, 2026 · OpenSSF OSV / OSV Scanner
Fix available
stdlib fixed in 1.25.13
Oct 10, 2026 · OpenSSF OSV / OSV Scanner
Fix available
stdlib fixed in 1.25.13
Oct 10, 2026 · Catalog
Updated
Previously, pathological inputs could close an unescaped '/' early, allowing for attack-controlled data to inject arbitrary content, potentially leading to XSS.
Oct 15, 2026 · OpenSSF OSV / OSV Scanner
Updated
Previously, pathological inputs could close an unescaped '/' early, allowing for attack-controlled data to inject arbitrary content, potentially leading to XSS.
Sources
- CVE.orgVulnerability recordCVE-2026-56858
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-56858
30-day exploitation probability 0.3%
first.org - OpenSSF OSV / OSV ScannerPackage advisoryGO-2026-6091
Fix Javascript regexp context tracking in html/template
osv.dev
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.