KEVWire

Security intelligence, with context.

Response snapshot Oct 29, 2026, 18:26 UTC

Back to the wire
Permalink
VulnerabilityCVE-2026-61846

Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage

Crass recursively parses CSS simple blocks and functions without a depth guard. An attacker-controlled value containing many deeply nested blocks can recurse until Ruby raises SystemStackError: stack level too deep, or can cause excessive memory usage. This is fixed in Crass 1.0.

At a glance

Exploited
Not known
Severity
6.3 Medium (CVSS 4.0)
Chance of exploitation
Not estimated
Sources
1 source

What to do

GitHub lists first patched versions: crass: 1.0.7. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-6jxj-px6v-747w (opens a new tab)

What happened

Impact

Crass recursively parses CSS simple blocks and functions without a depth guard. An attacker-controlled value containing many deeply nested blocks can recurse until Ruby raises SystemStackError: stack level too deep, or can cause excessive memory usage.

Patches

This is fixed in Crass 1.0.7, which adds a configurable depth limit with a conservative default.

Continue reading

Workarounds

Add SystemStackError handling around Crass calls in your application. Buy more RAM.

Affected package ranges reported by GitHub: crass: < 1.0.7

Scores and how they were measured

CVSS base severity

6.3

Version 4.0As of

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

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-6jxj-px6v-747w (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-6jxj-px6v-747w, 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 29). Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage (CVE-2026-61846). https://kevwire.com/record/CVE-2026-61846

MLA

"Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage (CVE-2026-61846)." KEVWire, 29 Oct. 2026, kevwire.com/record/CVE-2026-61846.

Chicago

KEVWire. "Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage (CVE-2026-61846)." Last modified October 29, 2026. https://kevwire.com/record/CVE-2026-61846.

Evidence summary (plain text)

Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage (Oct 29, 2026).
Crass recursively parses CSS simple blocks and functions without a depth guard. An attacker-controlled value containing many deeply nested blocks can recurse until Ruby raises SystemStackError: stack level too deep, or can cause excessive memory usage.

This is fixed in Crass 1.0.7, which adds a configurable depth limit with a conservative default.

Add SystemStackError handling around Crass calls in your application. Buy more RAM.
CVSS 6.3 (version 4.0; evidence as of Oct 29, 2026; https://github.com/advisories/GHSA-6jxj-px6v-747w).
Sources:
GitHub-reviewed advisory GHSA-6jxj-px6v-747w: https://github.com/advisories/GHSA-6jxj-px6v-747w
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
Record ID: CVE-2026-61846.
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 29, 2026, 18:26 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.

Record JSON

Your account

Email alerts

Email alerts are coming as part of KEVWire Premium: join the waitlist. To follow your stack today, use its RSS feed, which honors your filters, or connect an AI agent through the API.

Suggest an improvement

Ideas, missing sources, corrections, and bugs are all welcome. No account needed. Suggestions are reviewed by a person before anything changes.

Record details

Record detail