Security readout for executives and security teams
Plain-English summary
CVE-2021-26195 is a reported heap buffer overflow in JerryScript 2.4.0 while parsing numbers. For executives, the concern is memory corruption in a JavaScript engine, especially where untrusted script content is processed. The supplied sources do not provide CVSS, affected downstream products, active exploitation, or a confirmed fix.
Executive priority
Handle as an inventory and exposure check rather than an emergency by default. Escalate if JerryScript 2.4.0 is embedded in internet-facing or user-scriptable products. The lack of severity data and exploitation evidence limits confidence in urgency.
Technical view
The CVE describes a heap-buffer-overflow in `lexer_parse_number` in `js-lexer.c` in JerryScript 2.4.0. No CWE, CVSS vector, exploit maturity, or patch details are provided in the source bundle. Exposure depends on whether JerryScript 2.4.0 is embedded and reachable through attacker-controlled JavaScript parsing.
Likely exposure
Confirmed source evidence only names JerryScript 2.4.0. Likely exposure is in applications, firmware, or embedded systems that bundle this engine and parse untrusted JavaScript. No downstream vendors, package names, or vulnerable configurations are identified in the provided sources.
Exploitation context
The bundle says CISA KEV is false and provides no evidence of active exploitation. It references a public GitHub issue, but no exploit status or weaponized use is included here. Practical risk depends on attacker ability to make the target parse crafted JavaScript input.
Researcher notes
The source bundle is sparse: one CVE description and a GitHub issue reference. Do not assume affected downstream products, exploitability, or remediation details beyond JerryScript 2.4.0 until vendor issue or release data is reviewed.
Mitigation direction
- Inventory codebases, firmware, and third-party components for JerryScript 2.4.0.
- Check JerryScript project guidance and issue 4442 for fixed versions or patches.
- Restrict untrusted JavaScript input where JerryScript is embedded.
- Prioritize remediation where parsing is remotely reachable or user-controlled.
Validation and detection
- Confirm the deployed JerryScript version in builds and firmware SBOMs.
- Trace whether external users can supply JavaScript parsed by JerryScript.
- Review crash reports for heap-buffer-overflow indicators in `lexer_parse_number`.
- Verify any vendor patch or version change against project release notes.
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.
CVE-2021-26195 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/jerryscript-project/jerryscript/issues/4442CVE reference · x_refsource_CONFIRM
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.