Vector: Arbitrary file write in the file sink via templated path (path traversal). (CVE-2026-77621) | HOL Guard CVE

Critical · CVSS 9.3CVE-2026-77621

Vector: Arbitrary file write in the file sink via templated path (path traversal).

Answer in brief

CVE-2026-77621 records a Critical severity (CVSS 9.3) vulnerability in Vector: Arbitrary file write in the file sink via templated path (path traversal).. The current sources do not mark it as known exploited. The current feed maps vectordotdev/vector (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 22, 2026Updated Sep 22, 2026Source checked Sep 22, 2026First seen by HOL Sep 22, 2026Material review Sep 22, 2026

Upstream Advisory

Key facts

Risk: Critical · CVSS 9.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 9.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps vectordotdev/vector (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
vectordotdev/vectorgeneric	>= 0.10.0, < 0.57.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for vectordotdev/vector.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 22, 2026

Sources and claim methodology

Upstream source description

Vector is a high-performance observability data pipeline. From 0.10.0 until 0.57.0, the file sink renders its templated path from event fields and opens the result without confining it to an intended directory. When an untrusted source supplies an event field used by the path template, the value can contain an absolute path or parent-directory traversal, causing Vector to create parent directories and create or overwrite files outside the intended location with the Vector process privileges. The resulting file write can modify sensitive files and can lead to code execution when a scheduled task, authorization file, or subsequently executed script is targeted. This issue is fixed in version 0.57.0.

Quoted source text, attributed separately from HOL analysis.