- Exploited
- No known exploitation
- Fix
- Fixed in 5.9.3
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 5.9.3.
- Last modified
- 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? →
- 24/100 · provisional
- The rating the maker of the software gives it. Shown when it differs from the CVSS level.What do these mean? →
- Medium (ghsa)
- 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
Summary
The devalue JavaScript serialization library can, for some crafted inputs, create objects with an own `__proto__` property when parsing data, which this update now blocks as a defensive measure. On its own this does not enable prototype pollution, and the maintainers consider real-world impact very unlikely.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
This is another instance of https://github.com/sveltejs/devalue/security/advisories/GHSA-mwv9-gp5h-frr4, where some payloads could cause parse to create objects with a __proto__ own property. This on its own is not enough to cause prototype pollution, and indeed this is actually how JSON.parse works, but we decided to be a little more defensive here and not allow the creation of objects with __proto__ own-properties. It is very unlikely for this to cause any issues.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure?/25Unknown. No advisory context yet
- Reach20/20devalue: 24.5M downloads a week
- Severity4/10Rated medium by ghsa
- No patch0/5No signal
What would change the score
- Would score about 79 if added to CISA KEV
- Would score about 74 if CISA's SSVC rates exploitation active
- Would score about 46 if advisories confirm default setups are exposed
Impact
What to do
Upgrade to a fixed version: 5.9.3.
Timeline
- Advisory published
- Record last updated
Affected versions
- devaluenpm
fixed in 5.9.3
Evidence 4
- Advisory
- Repository
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about GHSA-4Q55-J62X-FR9H
Is GHSA-4Q55-J62X-FR9H 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
Which versions are affected by GHSA-4Q55-J62X-FR9H?
devalue (npm): before 5.9.3.Source: cve.now feed data
How do I fix GHSA-4Q55-J62X-FR9H?
Upgrade to a fixed version: 5.9.3.Source: cve.now feed data