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VulnerabilityPublished Updated

CVE-2026-68749: rrrene html_sanitize_ex · ReDoS

Affects rrrene html_sanitize_exSource CVE Database V5

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Not known to be exploited · CVSS 8.2 High : upgrade to 1.5.3 or 1.4.5 soon.

Data as of 5 Nov 2026, 00:01 UTC

CVSS 4.0 base score
8.2High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.8% chance of exploitation in 30 days – higher than 56% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 1.5.3, 1.4.5
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 6 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: evidence found.

    Public exploit code: GitHub proofs of concept

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.

What to do

Upgrade rrrene html_sanitize_ex to 1.5.3 or 1.4.5.

Affected software

ProductAffectedFixed in
rrrenehtml_sanitize_exAffected
  • >=1.5.0-rc.0 <1.5.3
Fixed in
  • 1.5.3
rrrenehtml_sanitize_exAffected
  • >=0.3.1 <1.4.5
Fixed in
  • 1.4.5
rrrenehtml_sanitize_exAffected
  • ≥ 21f90012eb21aa36f4e3701b7547e12faf0f3c8b, < 4f4bd9eb254881462c0461fbab74b29188c2c133
Fixed in–
Hexhtml_sanitize_expkg:hex/html_sanitize_exOther threatsAffected
  • >=0.3.1 <1.4.5
  • >=1.5.0-rc.0 <1.5.3
Fixed in
  • 1.4.5
  • 1.5.3

CPE configurations (1)

  • cpe:2.3:a:rrrene:html_sanitize_ex:*:*:*:*:*:*:*:*

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

If you cannot patch yet, consider limiting the size of CSS inputs passed to the scrubber or implementing application-level request rate limiting to reduce the risk of CPU exhaustion. Monitor application responsiveness and resource usage to detect potential exploitation attempts.

Description

Inefficient Regular Expression Complexity vulnerability in the CSS scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to exhaust server CPU via a long CSS declaration in sanitized HTML. The declaration regex in HtmlSanitizeEx.Scrubber.CSS.scrub/1 matches the property name with an unbounded greedy [-\w]+ followed by a mandatory :, so a long run of word characters not followed by a colon makes the engine give back one character at a time and retry the colon at every start offset. The work is quadratic in the length of the run, and no length cap is applied to the CSS handed to the scrubber. An 80 KB <style> body costs roughly 2.4 seconds of scheduler time, so a few concurrent requests saturate the BEAM scheduler pool and make the application unresponsive. The impact is CPU exhaustion only. Nothing is read, modified or disclosed. This issue affects html_sanitize_ex: from 0.3.1 before 1.4.5 and from 1.5.0-rc.0 before 1.5.3.

References

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