Security readout for executives and security teams
Plain-English summary
Foundation Sites 6.3.3 and earlier include regular expressions that can be forced into excessive processing, potentially making affected web applications unavailable. The sources do not identify active exploitation or a confirmed patch, so urgency depends on whether exposed application paths process attacker-controlled input through the vulnerable code.
Executive priority
Treat as a high-priority availability risk where Foundation Sites is internet-facing or processes untrusted input. Prioritize inventory and vendor-guided remediation before assuming a patch exists.
Technical view
CVE-2020-26304 is a CWE-1333 ReDoS issue in foundation-sites. The CVSS 4.0 vector shows network attackability, low complexity, no privileges, no user interaction, and high availability impact. The advisory states fix availability was unknown at publication.
Likely exposure
Organizations using foundation-sites 6.3.3 or earlier may be exposed, especially where user-supplied values reach affected front-end parsing or validation logic.
Exploitation context
No KEV listing is present, and the provided sources do not state active exploitation. Public advisory and GitHub issue details exist, which may help defenders and attackers understand the risk.
Researcher notes
Evidence supports ReDoS in Foundation Sites 6.3.3 and prior, with high availability impact. Affected metadata in the bundle is limited, and fix status is explicitly unclear, so validate dependency presence and exposure path before escalation.
Mitigation direction
- Inventory applications and dependencies for foundation-sites 6.3.3 or earlier.
- Check Foundation project advisories and issue 12180 for current fix guidance.
- Upgrade only according to verified vendor guidance or tested maintained releases.
- Limit attacker-controlled input reaching affected parsing or validation paths.
- Use request rate limits and availability monitoring for exposed affected applications.
Validation and detection
- Review package-lock, yarn.lock, pnpm-lock, or SBOM entries for foundation-sites versions.
- Map public routes that load or execute foundation-sites code.
- Confirm whether untrusted input reaches affected Foundation regex handling.
- Run controlled performance regression tests without using production traffic.
- Monitor application CPU spikes and request latency around relevant public routes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-1333: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2020-26304 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.7 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/U:Green
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/U:Green——Primary CVE scoreVulnerability scoring details
Base CVSS 4.0 score
8.7HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/U:Green
Source materials
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Inefficient Regular Expression Complexity
Inefficient Regular Expression Complexity represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.