Inefficient Regular Expression Complexity vulnerability in the CSS scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to… (CVE-2026-68749)
A vulnerability in the CSS scrubber of the html_sanitize_ex library allows an unauthenticated remote attacker to cause CPU exhaustion by sending a long CSS declaration. The issue arises from an inefficient regular expression that processes CSS property names with unbounded greedy matching, leading to quadratic time complexity. This can saturate the server's scheduler pool and make the application unresponsive. The vulnerability affects html_sanitize_ex versions from 0.3.1 up to but not including 1.5.3. The impact is limited to denial of service via CPU exhaustion; no data confidentiality or integrity is affected.
AI Analysis
Technical Summary
The html_sanitize_ex library contains an inefficient regular expression in its CSS scrubber (HtmlSanitizeEx.Scrubber.CSS.scrub/1) that matches CSS property names using an unbounded greedy pattern followed by a colon. When processing a long run of word characters without a colon, the regex engine backtracks extensively, causing quadratic CPU time relative to input length. This allows an unauthenticated remote attacker to exhaust server CPU resources by submitting large CSS declarations in sanitized HTML, leading to denial of service. The vulnerability affects versions from 0.3.1 before 1.5.3. No patch or remediation details are provided in the source data.
Potential Impact
The vulnerability results in CPU exhaustion on the server due to inefficient regex processing, causing denial of service by making the application unresponsive. There is no impact on confidentiality or integrity of data. The attack requires no authentication and can be triggered remotely by submitting crafted CSS in sanitized HTML inputs.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider limiting the size of CSS inputs passed to the html_sanitize_ex scrubber or applying external rate limiting to reduce the risk of CPU exhaustion. Monitor for unusually high CPU usage related to CSS sanitization processes.
Inefficient Regular Expression Complexity vulnerability in the CSS scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to… (CVE-2026-68749)
Description
A vulnerability in the CSS scrubber of the html_sanitize_ex library allows an unauthenticated remote attacker to cause CPU exhaustion by sending a long CSS declaration. The issue arises from an inefficient regular expression that processes CSS property names with unbounded greedy matching, leading to quadratic time complexity. This can saturate the server's scheduler pool and make the application unresponsive. The vulnerability affects html_sanitize_ex versions from 0.3.1 up to but not including 1.5.3. The impact is limited to denial of service via CPU exhaustion; no data confidentiality or integrity is affected.
CVSS v3.1
Score 7.5high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The html_sanitize_ex library contains an inefficient regular expression in its CSS scrubber (HtmlSanitizeEx.Scrubber.CSS.scrub/1) that matches CSS property names using an unbounded greedy pattern followed by a colon. When processing a long run of word characters without a colon, the regex engine backtracks extensively, causing quadratic CPU time relative to input length. This allows an unauthenticated remote attacker to exhaust server CPU resources by submitting large CSS declarations in sanitized HTML, leading to denial of service. The vulnerability affects versions from 0.3.1 before 1.5.3. No patch or remediation details are provided in the source data.
Potential Impact
The vulnerability results in CPU exhaustion on the server due to inefficient regex processing, causing denial of service by making the application unresponsive. There is no impact on confidentiality or integrity of data. The attack requires no authentication and can be triggered remotely by submitting crafted CSS in sanitized HTML inputs.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider limiting the size of CSS inputs passed to the html_sanitize_ex scrubber or applying external rate limiting to reduce the risk of CPU exhaustion. Monitor for unusually high CPU usage related to CSS sanitization processes.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-8rjf-8hw9-j63g
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-68749"]
- Ecosystems
- []
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a7b6fd2bf8831d5393ea5a4
Added to database: 08/11/2026, 18:54:10 UTC
Last enriched: 08/11/2026, 18:57:17 UTC
Last updated: 08/12/2026, 02:40:59 UTC
Views: 3
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