svg-sanitizer 1.0.0 before 1.1.0 ReDoS and Fail-Open via image-set CSS Stripping
Only svg-sanitizer 1.0.0 before 1.1.0 with removeRemoteReferences(true) is affected. The fix is in 1.1.0.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- Proof of concept public, per CISA
- Fix
- Fixed in 1.1.0
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 1.1.0.
- Exploitation15/40CISA rates a proof of concept as public
- Exposure17/25No login or user action needed, reachable over the network without a login · Data gap: Advisories don't say whether default setups are affected
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity8.2/10CVSS 8.2
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
- Would score about 45 if advisories confirm default setups are exposed
CVE-2026-121445 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.2 (high) and affects svg-sanitizer; fixed in 1.1.0.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 40/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Fix
- Fixed in 1.1.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: no
- Technical impact: partial
Summary
darylldoyle svg-sanitizer from 1.0.0 before 1.1.0 contains a regular expression denial of service vulnerability in the image-set pattern of stripRemoteCssTokens() when removeRemoteReferences is enabled. Attackers can submit SVGs with many unclosed image-set tokens to exhaust CPU, or trigger PCRE limits causing sanitize() to throw a TypeError and leave unsanitized content.
What to do
Upgrade to a fixed version: 1.1.0.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- darylldoyle svg-sanitizer
From 1.0.0 · fixed in 1.1.0
Evidence 2
- Advisory
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-121445
Is CVE-2026-121445 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A crafted SVG under 1 MB can hold a worker for tens of seconds through CPU exhaustion. Also, sanitize() throws a TypeError instead of returning false, which can leave unsanitized content in place.Source: github.com, vulncheck.com
Which versions are affected by CVE-2026-121445?
svg-sanitizer: from 1.0.0 before 1.1.0.Source: cve.now feed data
Am I affected, and how do I check?
Versions 1.0.0 up to but not including 1.1.0 are affected, and only when the removeRemoteReferences option is enabled with removeRemoteReferences(true). To check, look at the installed svg-sanitizer version and whether that option is set in the code that calls it.Source: github.com, vulncheck.com
How do I fix CVE-2026-121445?
Upgrade svg-sanitizer to 1.1.0, the fixed version.Source: github.com, vulncheck.com