svg-sanitizer 0.11.0 before 1.1.0 Algorithmic Complexity DoS via use Reference Graph
Affects svg-sanitizer 0.11.0 through 1.0.0 when sanitize() processes SVG with layered use references. Fixed in 1.1.0.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 1.1.0
- Who is exposed
- Default setups
Do first: Check every install: default setups are affected.
- Exploitation0/40No signal
- Exposure25/25Default setups, CISA rates it automatable
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity8.7/10CVSS 8.7
- No patch0/5No signal
What would change the score
- Would score about 74 if added to CISA KEV
- Would score about 69 if CISA's SSVC rates exploitation active
CVE-2026-121444 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.7 (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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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? →
- 34/100 · 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? →
- Default setups
- 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: none
- Automatable: yes
- Technical impact: partial
Summary
svg-sanitizer from 0.11.0 before 1.1.0 contains an algorithmic complexity denial of service vulnerability in hasInfiniteLoop() and countUse() of the use reference-graph analysis. Attackers can upload a small layered SVG with 15 levels of fanned-out use elements, forcing exponential path enumeration that pins PHP workers for hours.
What to do
Check every install: default setups are affected.
Upgrade to a fixed version: 1.1.0.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- darylldoyle svg-sanitizer
From 0.11.0 · 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-2026-121444
Is CVE-2026-121444 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. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A single small crafted SVG can force sanitize() into very large amounts of CPU work, growing super-polynomially with the depth of nested use references. This can pin PHP workers and cause denial of service.Source: github.com, vulncheck.com
Which versions are affected by CVE-2026-121444?
svg-sanitizer: from 0.11.0 before 1.1.0.Source: cve.now feed data
Am I affected, and how do I check?
Versions from 0.11.0 up to 1.0.0 of the Composer package enshrined/svg-sanitize are affected when attacker-supplied SVG with layered use references is passed to sanitize(). Check the installed version of enshrined/svg-sanitize in your project's dependency lock file.Source: github.com, vulncheck.com
How do I fix CVE-2026-121444?
Upgrade to svg-sanitizer 1.1.0, the fixed version. The sources do not list a workaround.Source: github.com, vulncheck.com