Security readout for executives and security teams
Plain-English summary
Knwl.js can be forced into excessive CPU work while parsing specially shaped text. If an application feeds user-controlled text into affected Knwl.js versions, attackers may degrade availability without authentication. Sources state versions 1.0.2 and prior are affected and that no patch was known at publication.
Executive priority
Prioritize review if Knwl.js handles public input in production services, because the impact is service availability. If usage is internal, trusted, or non-runtime, urgency is lower but dependency replacement should still be planned due to absent patch evidence.
Technical view
CVE-2020-26306 is a CWE-1333 regular expression denial-of-service issue in Knwl.js text parsers. The CVSS v4.0 score is 8.7, driven by network reachability, low complexity, no privileges, no user interaction, and high availability impact. The supplied sources do not identify confidentiality or integrity impact.
Likely exposure
Exposure is most likely in JavaScript applications that include Knwl.js 1.0.2 or earlier and parse untrusted or externally supplied text, such as messages, forms, documents, or API input. The source bundle does not establish whether downstream packages bundle Knwl.js.
Exploitation context
The CVE is not listed as CISA KEV in the provided bundle, and no cited source states active exploitation. The practical risk is availability loss when attacker-controlled text reaches the vulnerable regular expressions. No exploit steps are provided here.
Researcher notes
Evidence is narrow but consistent: GHSL reports ReDoS in Knwl.js and the CVE assigns high availability impact. The affected-version text names 1.0.2 and prior, while the provided affected metadata is sparse, so confirm exact package coordinates during inventory.
Mitigation direction
- Check vendor and project guidance before assuming a patched release exists.
- Remove or replace Knwl.js where it processes untrusted text.
- Restrict Knwl parsing to trusted or bounded-size inputs.
- Add request timeouts and CPU safeguards around text parsing paths.
- Monitor the GitHub issue and advisory for patch status changes.
Validation and detection
- Review SBOMs and lockfiles for Knwl.js versions 1.0.2 or earlier.
- Map every path where user-controlled text reaches Knwl parsing.
- Confirm whether parsing runs in request-critical services or background jobs.
- Check existing length limits, timeouts, and worker isolation controls.
- Track compensating controls as temporary risk treatment, not a vendor fix.
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-2020-26306 mapping review
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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
- CVE List V5 sourceCVE List V5
- https://securitylab.github.com/advisories/GHSL-2020-296-redos-Knwl.js/CVE reference
- https://github.com/benhmoore/Knwl/issues/106CVE reference
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.