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Response snapshot Oct 27, 2026, 13:06 UTC

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VulnerabilityCVE-2026-84370

SVGO: removeScripts allows executable links through namespace and control-character bypasses

SVGO's opt-in `removeScripts` plugin failed to remove some executable links. Namespace-prefixed SVG anchors and URL schemes containing ASCII tabs or newlines could bypass its checks.

Published Updated

At a glance

Exploited
Not known
Severity
8.2 High (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

GitHub lists first patched versions: svgo: 2.8.4; svgo: 3.3.5; svgo: 4.1.0. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-w27v-7q3p-w38r (opens a new tab)

What happened

## Summary

SVGO's opt-in `removeScripts` plugin failed to remove some executable links. Namespace-prefixed SVG anchors and URL schemes containing ASCII tabs or newlines could bypass its checks. Applications that used this plugin as their only protection for untrusted SVG input could expose users to cross-site scripting (XSS).

SVGO is an optimizer rather than a comprehensive sanitization library, but `removeScripts` is maintained for consumers that already rely on it to remove common script execution paths.

## Details

Continue reading

Two related bypasses were present:

1. The plugin inspected unprefixed SVG ` ` elements but did not recognize namespace-prefixed SVG anchors such as ` ` when the prefix was bound to the SVG namespace. Their executable `href` or namespaced `*:href` values remained intact. 2. The URL check did not account for ASCII tab, line-feed, or carriage-return characters embedded in a scheme.

Browsers remove these characters before parsing the scheme, so values such as `java script:` could remain executable after bypassing the plugin's `javascript:` check.

Anchors in unrelated custom namespaces are not executable SVG anchors and remain untouched.

## Impact

If an application optimized attacker-controlled SVGs with `removeScripts` and then served the result in an active browser context, a victim could follow a link that executes script in the SVG's origin. Depending on the embedding and origin configuration, this could expose cookies or local storage, modify content, or perform actions as the victim.

The plugin is opt-in, so consumers that do not enable it are not relying on the affected behavior. Typical local optimization of trusted SVG files is not affected.

## Patches

Upgrade to one of the following releases for the maintained release line in use:

| Release line | Patched version | Plugin | | --- | --- | --- | | v2 | 2.8.4 | `removeScriptElement` | | v3 | 3.3.5 | `removeScriptElement` | | v4 | 4.1.0 | `removeScripts` |

The fix makes SVG anchor handling namespace-aware and strips ASCII tabs, line feeds, and carriage returns before checking executable URL schemes.

SVGO v1 is no longer maintained. Users of v1 should upgrade to a supported release line.

## Workarounds

For hostile input, use a dedicated SVG sanitization tool before passing the SVG to SVGO. Applications can also reject links from untrusted SVG input and avoid serving user-controlled SVGs in an active same-origin context.

## References

- v4 fix: https://github.com/svg/svgo/pull/2268 - related executable URL hardening: https://github.com/svg/svgo/pull/2263 - v3 backport: https://github.com/svg/svgo/pull/2269 - v2 backport: https://github.com/svg/svgo/pull/2272 - v4.1.0 release: https://github.com/svg/svgo/releases/tag/v4.1.0 - v3.3.5 release: https://github.com/svg/svgo/releases/tag/v3.3.5 - v2.8.4 release: https://github.com/svg/svgo/releases/tag/v2.8.4

Affected package ranges reported by GitHub: svgo: >= 1.0.0, < 2.8.4 svgo: >= 3.0.0, < 3.3.5 svgo: >= 4.0.0, < 4.1.0

Scores and how they were measured

CVSS base severity

8.2

Version 3.1As of

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

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-w27v-7q3p-w38r (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-w27v-7q3p-w38r, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 26). SVGO: removeScripts allows executable links through namespace and control-character bypasses (CVE-2026-84370). https://kevwire.com/record/CVE-2026-84370

MLA

"SVGO: removeScripts allows executable links through namespace and control-character bypasses (CVE-2026-84370)." KEVWire, 26 Oct. 2026, kevwire.com/record/CVE-2026-84370.

Chicago

KEVWire. "SVGO: removeScripts allows executable links through namespace and control-character bypasses (CVE-2026-84370)." Last modified October 26, 2026. https://kevwire.com/record/CVE-2026-84370.

Evidence summary (plain text)

SVGO: removeScripts allows executable links through namespace and control-character bypasses (Sep 8, 2026).
SVGO's opt-in `removeScripts` plugin failed to remove some executable links. Namespace-prefixed SVG anchors and URL schemes containing ASCII tabs or newlines could bypass its checks. Applications that used this plugin as their only protection for untrusted SVG input could expose users to cross-site scripting (XSS).

SVGO is an optimizer rather than a comprehensive sanitization library, but `removeScripts` is maintained for consumers that already rely on it to remove common script execution paths.
CVSS 8.2 (version 3.1; evidence as of Oct 26, 2026; https://github.com/advisories/GHSA-w27v-7q3p-w38r).
Sources:
GitHub-reviewed advisory GHSA-w27v-7q3p-w38r: https://github.com/advisories/GHSA-w27v-7q3p-w38r
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
Record ID: CVE-2026-84370.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 11:45 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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