chore(deps): bump undici and serverless

[dependabot]

Bumps undici and serverless. These dependencies needed to be updated together.
Updates undici from 6.24.1 to 6.27.0

Release notes

Sourced from undici's releases.

v6.27.0

⚠️ Security Release

This release line addresses 4 security advisories.

Action required: Upgrade to undici 6.27.0 or later.

npm install undici@^6.27.0

Note on patched version: the v6 fixes shipped in v6.27.0, not 6.26.0 — v6.26.0 contains only the chunked-EOF fix (#5308) and the version bump, none of the security fixes below.

The v6 line is not affected by the SOCKS5 advisories (GHSA-vmh5-mc38-953g, GHSA-hm92-r4w5-c3mj), the shared-cache disclosure (GHSA-pr7r-676h-xcf6), or the 8.x-only WebSocket regression (GHSA-38rv-x7px-6hhq).

Summary

Advisory	CVE	Severity (CVSS)	Fixed in	Fix commit
GHSA-vxpw-j846-p89q	CVE-2026-12151	High (7.5)	6.27.0	b7f252e7
GHSA-p88m-4jfj-68fv	CVE-2026-9679	Moderate (5.9)	6.27.0	25efa447
GHSA-g8m3-5g58-fq7m	CVE-2026-11525	Low (3.7)	6.27.0	25efa447
GHSA-35p6-xmwp-9g52	CVE-2026-6733	Low (3.7)	6.27.0	f4c31d60

---

High severity

WebSocket DoS via fragment count bypass — CVE-2026-12151

GHSA-vxpw-j846-p89q · CWE-400, CWE-770 Fix: b7f252e7 Backport WebSocket maxPayloadSize fixes (#5423, backported to v6 in #5428)

A malicious WebSocket server can stream a large number of small or empty continuation frames. Undici enforced a limit on cumulative payload size but did not limit the number of fragments per message, leading to unbounded memory growth and denial of service. All releases from 6.17.0 onward are affected.

• Affected: applications using new WebSocket(...) or WebSocketStream against untrusted endpoints.
• Workaround: none — upgrade is required.

---

Moderate severity

HTTP header injection via Set-Cookie percent-decoding — CVE-2026-9679

... (truncated)

Commits

• 551138c Bumped v6.27.0 (#5431)
• b7f252e Backport WebSocket maxPayloadSize fixes to v7.x (#5423) (#5428)
• 25efa44 fix(cookies): preserve values and parse SameSite strictly
• f4c31d6 fix: guard idle socket validation to skip fresh sockets (#5400)
• 768beac Bumped v6.26.0 (#5323)
• 7917b25 fix: validate EOF for chunked h1 responses (#5308)
• 3420499 Bumped v6.25.0 (#5029)
• d7a1e55 feat: add configurable maxPayloadSize for WebSocket (#4955)
• a9d1848 Do not mark v6.x releases as latest
• 0126586 Ignore local agent configuration files
• See full diff in compare view

Updates undici from 7.24.4 to 7.28.0

Release notes

Sourced from undici's releases.

v6.27.0

⚠️ Security Release

This release line addresses 4 security advisories.

Action required: Upgrade to undici 6.27.0 or later.

npm install undici@^6.27.0

Note on patched version: the v6 fixes shipped in v6.27.0, not 6.26.0 — v6.26.0 contains only the chunked-EOF fix (#5308) and the version bump, none of the security fixes below.

The v6 line is not affected by the SOCKS5 advisories (GHSA-vmh5-mc38-953g, GHSA-hm92-r4w5-c3mj), the shared-cache disclosure (GHSA-pr7r-676h-xcf6), or the 8.x-only WebSocket regression (GHSA-38rv-x7px-6hhq).

Summary

Advisory	CVE	Severity (CVSS)	Fixed in	Fix commit
GHSA-vxpw-j846-p89q	CVE-2026-12151	High (7.5)	6.27.0	b7f252e7
GHSA-p88m-4jfj-68fv	CVE-2026-9679	Moderate (5.9)	6.27.0	25efa447
GHSA-g8m3-5g58-fq7m	CVE-2026-11525	Low (3.7)	6.27.0	25efa447
GHSA-35p6-xmwp-9g52	CVE-2026-6733	Low (3.7)	6.27.0	f4c31d60

---

High severity

WebSocket DoS via fragment count bypass — CVE-2026-12151

GHSA-vxpw-j846-p89q · CWE-400, CWE-770 Fix: b7f252e7 Backport WebSocket maxPayloadSize fixes (#5423, backported to v6 in #5428)

A malicious WebSocket server can stream a large number of small or empty continuation frames. Undici enforced a limit on cumulative payload size but did not limit the number of fragments per message, leading to unbounded memory growth and denial of service. All releases from 6.17.0 onward are affected.

• Affected: applications using new WebSocket(...) or WebSocketStream against untrusted endpoints.
• Workaround: none — upgrade is required.

---

Moderate severity

HTTP header injection via Set-Cookie percent-decoding — CVE-2026-9679

... (truncated)

Commits

• 551138c Bumped v6.27.0 (#5431)
• b7f252e Backport WebSocket maxPayloadSize fixes to v7.x (#5423) (#5428)
• 25efa44 fix(cookies): preserve values and parse SameSite strictly
• f4c31d6 fix: guard idle socket validation to skip fresh sockets (#5400)
• 768beac Bumped v6.26.0 (#5323)
• 7917b25 fix: validate EOF for chunked h1 responses (#5308)
• 3420499 Bumped v6.25.0 (#5029)
• d7a1e55 feat: add configurable maxPayloadSize for WebSocket (#4955)
• a9d1848 Do not mark v6.x releases as latest
• 0126586 Ignore local agent configuration files
• See full diff in compare view

Updates serverless from 4.35.0 to 4.38.1

Release notes

Sourced from serverless's releases.

4.38.1

Maintenance

• Upgraded undici to 6.27.0, clearing security advisories reported against earlier versions of the bundled HTTP client: a Set-Cookie SameSite attribute downgrade (GHSA-g8m3-5g58-fq7m), HTTP header injection via Set-Cookie percent-decoding (GHSA-p88m-4jfj-68fv), and a WebSocket client denial-of-service (GHSA-vxpw-j846-p89q). (#13657)

4.38.0

Features

• Ruby 4.0 runtime support. Functions can now target the ruby4.0 Lambda runtime. (#13613)

  provider:
    name: aws
    runtime: ruby4.0

• New ${aws:partition} variable. Resolves to the AWS partition for the deployment region (e.g. aws, aws-cn, aws-us-gov) with no network call or credentials required. Makes ARNs in your configuration portable across commercial, GovCloud, and China partitions. (#12441, #13633)

  provider:
    iam:
      role:
        managedPolicies:
          - arn:${aws:partition}:iam::aws:policy/AmazonS3ReadOnlyAccess

• AgentCore: Python 3.14 support. Agent runtimes can now target python3.14. Runtime validation is also stronger, with supported runtimes validated against a single allowlist. (#13645)

  # AgentCore agent configuration
  runtime: python3.14

Bug Fixes

• API Gateway custom stage now used for the service endpoint URL and stage tags. When provider.apiGateway.stage is set to a value different from the deployment stage, the ServiceEndpoint output URL and the API Gateway stage tags now use that configured stage. Previously they used the deployment stage, producing an incorrect endpoint URL and attempting to tag a stage that did not exist. (#13636)

  provider:
    apiGateway:
      stage: customstage   # now reflected in ServiceEndpoint + stage tags

• Variable resolution no longer drops placeholders during re-entrant resolution. A JavaScript or TypeScript ${file(...)} resolver that calls resolveVariable() or resolveConfigurationProperty() mid-resolution opens a nested resolution pass. Under certain async timing this could leave the outer resolution looking inactive, causing a later nested placeholder to be left unresolved. Each pass now preserves and restores its context so the full dependency chain resolves reliably. (#13635)

• AgentCore: unpinned the default Buildpacks builder image and added a builder override. The previously hard-pinned heroku/builder digest is no longer used by default. (#13647, #13646)

Maintenance

• Bumped the AWS SDK group with 34 updates (#13632)

... (truncated)

Commits

• fb7ac39 chore: release 4.38.1 (#13658)
• 7565a78 chore(deps): bump undici (#13657)
• 56e78c1 chore: release 4.38.0 (#13651)
• 27dacea chore(deps): bump golang.org/x/mod in /binary-installer (#13650)
• 384a7e4 fix(agentcore): unpin heroku/builder digest; add artifact.image.builder overr...
• ea79235 fix(api-gateway): use resolved API Gateway stage for stage tags and service e...
• a2804b0 chore(deps): bump the npm_and_yarn group across 13 directories with 2 updates...
• 90183bc chore(deps): update package-lock.json (#13648)
• 64e189c feat(agentcore): support Python 3.14 and improve agent runtime validation (#1...
• 312a842 chore(deps): bump the actions group with 2 updates (#13641)
• Additional commits viewable in compare view

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[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/serverless-operations/serverless-step-functions@787

commit: 33864f4