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CVE Record

CVE-2026-27606: Rollup 4 has Arbitrary File Write via Path Traversal

Rollup is a module bundler for JavaScript. Versions prior to 2.80.0, 3.30.0, and 4.59.0 of the Rollup module bundler (specifically v4.x and present in current source) is vulnerable to an Arbitrary File Write via Path Traversal. Insecure file name sanitization in the core engine allows an attacker to control output filenames (e.g., via CLI named inputs, manual chunk aliases, or malicious plugins) and use traversal sequences (`../`) to overwrite files anywhere on the host filesystem that the build process has permissions for. This can lead to persistent Remote Code Execution (RCE) by overwriting critical system or user configuration files. Versions 2.80.0, 3.30.0, and 4.59.0 contain a patch for the issue.

CriticalCVSS 9.1Not KEV-listedUpdated
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Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

Rollup build tooling can be tricked into writing files outside its intended output folder. If an attacker can influence build inputs, aliases, or plugins, the build process could overwrite sensitive files with the build user’s permissions. This is a build-system risk, not ordinary website browsing exposure.

Executive priority

Treat this as urgent for teams that build JavaScript assets or ship products using Rollup. Prioritize patching build environments and release pipelines first, because compromise there can affect downstream artifacts and developer systems.

Technical view

CVE-2026-27606 is a Rollup path traversal flaw caused by insecure output filename sanitization. Affected versions can accept controlled output names containing traversal sequences and perform arbitrary file writes. Sources list patched versions 2.80.0, 3.30.0, and 4.59.0.

Likely exposure

Organizations using Rollup in CI, developer workstations, packaging systems, or vendor products may be exposed if affected versions are present. Risk is higher where builds consume untrusted configuration, plugins, chunk aliases, or named inputs.

Exploitation context

The provided sources do not show CISA KEV listing or confirmed active exploitation. The described impact is serious because compromise occurs through the build environment and could become persistent if sensitive configuration or startup files are overwritten.

Researcher notes

Focus validation on where attacker influence reaches Rollup’s output naming surfaces: CLI named inputs, manual chunk aliases, and plugins. Do not assume public-facing runtime exposure unless the application allows untrusted parties to affect the build process.

Mitigation direction

  • Upgrade Rollup to 2.80.0, 3.30.0, 4.59.0, or later as appropriate.
  • Refresh lockfiles and verify the resolved Rollup version actually changed.
  • Review vendor advisories for bundled Rollup in Red Hat or other packaged products.
  • Restrict untrusted Rollup plugins, build configs, manual chunk names, and named inputs.
  • Run builds with least privilege in isolated CI workspaces.

Validation and detection

  • Search package manifests and lockfiles for affected Rollup version ranges.
  • Confirm CI and release builds use the patched resolved dependency.
  • Identify build paths that accept external plugins, configuration, or input names.
  • Review build user permissions and writable paths on CI runners.
  • Check relevant Red Hat errata or CSAF status for packaged dependencies.
Prepared
Confidence
high
Sources
12

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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 · medium confidence lookup

CWE-22: File access and web shell behavior lookup

File traversal and upload weaknesses can lead teams to review file, web shell, execution, and collection telemetry. 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.

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description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
description · low confidence lookup

File access behavior lookup

The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-27606 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Critical
CVSS
9.1 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Official CVE source material

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.

2CVSS vectors
5Timeline events
2ADP providers
21Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: yesTechnical Impact: total

CVSS vector scores

2 official scores

We 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.

ScoreVersionSeverityVectorExploitImpactSource
9.1CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N3.95.2redhat-SADP
8.8CVSS 4.0HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P——GitHub_M

Vulnerability scoring details

Base CVSS 4.0 score

8.8High
CVSS 4.0 vector shape for CVE-2026-27606Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADProllup: Rollup: Remote Code Execution via Path Traversal Vulnerability
other:Red Hat severity ratingcvssV3_1
  • 2026-02-25T04:01:24.449Z: Reported to Red Hat.
  • 2026-02-25T02:08:06.682Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
rolluprollup< 2.80.0, >= 3.0.0, < 3.30.0, >= 4.0.0, < 4.59.0Listed
Weakness

CWE details

CWE-22

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-22 · source CWE mapping

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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