Security readout for executives and security teams
Plain-English summary
CVE-2026-3449 affects the npm package @tootallnate/once before 3.0.1. When an abort signal is used, a promise may never finish, causing dependent application work to hang. Business impact is mainly degraded availability, such as stalled requests or blocked workers, not data theft or code execution based on available sources.
Executive priority
Treat as a normal-priority availability fix for affected JavaScript services. Prioritize internet-facing or worker-heavy systems where hung operations can consume capacity. It does not currently warrant emergency response absent evidence of exploitation or severe service impact.
Technical view
The flaw is an incorrect control-flow scoping issue in promise resolving when the AbortSignal option is used. After abort, await or .then() consumers can remain pending indefinitely. Sources classify this as CWE-705 with CVSS 4.0 score 4.8 and low availability impact. The referenced commit appears to address the behavior.
Likely exposure
Exposure is likely in Node.js applications that depend on @tootallnate/once before 3.0.1, directly or transitively, and use AbortSignal-related code paths. Applications not using abort behavior may have limited practical exposure, though vulnerable dependency presence should still be tracked.
Exploitation context
No active exploitation is indicated by the provided sources, and the CVE is not in CISA KEV. Exploitation impact appears to require triggering affected abort-handling paths, leading to indefinite pending promises and potential availability degradation rather than confidentiality or integrity compromise.
Researcher notes
The source bundle’s affected version field is sparse, but the description clearly states versions before 3.0.1 are vulnerable. Analysis should focus on dependency reachability and AbortSignal usage. Avoid assuming broad impact without confirming affected code paths.
Mitigation direction
- Upgrade @tootallnate/once to version 3.0.1 or later where feasible.
- Regenerate and review lockfiles to remove vulnerable transitive versions.
- Prioritize services where stalled requests or workers affect availability.
- Check package maintainer and Snyk guidance for any updated remediation details.
Validation and detection
- Inventory direct and transitive @tootallnate/once versions in applications.
- Flag any deployed version earlier than 3.0.1.
- Review whether affected code paths use the AbortSignal option.
- Test abort behavior safely in staging after remediation.
- Confirm dependency scanners no longer report CVE-2026-3449.
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-705: 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-2026-3449 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
- Medium
- CVSS
- 4.8 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
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.
SSVC decision data
CVSS vector scores
2 official scoresWe 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:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P——snykCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P1.81.4snykVulnerability scoring details
Base CVSS 4.0 score
4.8MediumVector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
Base CVSS 3.1 score
3.3LowVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://security.snyk.io/vuln/SNYK-JS-TOOTALLNATEONCE-15250612CVE reference, snyk
- https://github.com/TooTallNate/once/issues/8CVE reference, snyk
- https://github.com/TooTallNate/once/commit/b9f43cc5259bee2952d91ad3cdbd201a82df448aCVE reference, snyk
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.
Incorrect Control Flow Scoping
Incorrect Control Flow Scoping represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.