CVE-2026-100355 - Campfire is a web-based chat application. In version 1.4.4 and earlier, when a Campfire message contains a link, the ser
Campfire is a web-based chat application. In version 1.4.4 and earlier, when a Campfire message contains a link, the server fetches it to build an OpenGraph unfurl preview. `RestrictedHTTP::PrivateNetworkGuard` relied on Ruby's `IPAddr#private? `` IPAddr#loopback?`, and `IPAddr#link_local?` predicates plus IPv4-mapped and IPv4-compatible checks, which do not cover several special-use ranges. An authenticated user can post a link to a hostname resolving to CGNAT `100.64.0.0/10`, NAT64 `64:ff9b::/96` or `64:ff9b:1::/48`, or 6to4 `2002::/16` to bypass the guard and cause server-side requests to internal network resources. The NAT64 and 6to4 ranges can embed an internal IPv4 target. Confidentiality impact is limited to returned OpenGraph metadata, and most internal endpoints return none. There is no integrity or availability impact. An initial fix was released in version 1.4.5.
LOW
Severity & confidence
Source severitylow
Platform severitylow
Confidencehigh
Exploitationunknown
CVSS3.1
Affected
Reporting sources (1)
NIST NVD - National Vulnerability Database
Timeline & provenance
Published2026-10-30T14:16:35
Last updated2026-11-02T13:59:26
Ingested2026-11-01T16:33:30
FreshnessNEAR-REAL-TIME
Threat typevulnerability
Recommended action
No recommended action published with this item - review the original source.
Next steps
- Identify affected systems in your environment.
- Apply the vendor patch or mitigation guidance.
- Review logs for indicators described in the advisory.
- Follow the affected vendor/product to track updates.
Confidence explanation
Reported by a government or cert-grade source (CISA, NCSC, NVD, ENISA, MSRC).
Source type: standards · Original: NIST NVD - National Vulnerability Database
