Sveltejs devalue before 5.6.3 contains a prototype pollution vulnerability that allows attackers to alter object
Source GCVE Database
Not known to be exploited · CVSS 2.1 Low : upgrade to 5.6.3 when convenient.
Data as of 8 Nov 2026, 06:33 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 2.1 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 4.4 |
- Patch
- Available – fixed in 5.6.3
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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), the Metasploit, Exploit-DB and nuclei-templates index as of 7 Nov 2026.
What to do
Upgrade devalue to 5.6.3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| sveltejsdevalue | Affected
| Fixed in
|
npmdevaluepkg:npm/devalueOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Since the vulnerability affects versions before 5.6.3, upgrading to version 5.6.3 or later is implied as the remediation. Users should apply this update once available.
Description
Sveltejs devalue versions before 5.6.3 contain a prototype pollution vulnerability. This flaw allows attackers to manipulate object prototypes by providing untrusted data to the uneval function. When the affected code evaluates this data, it results in objects with polluted prototypes, causing output data to differ in structure from the original input. The vulnerability has a medium severity rating with a CVSS score of 4.4.