Security Digest · Vulnerability record
CVE-2026-105863: Payload authentication token field handling issue
Payload is a free and open source headless content management system.
CVSS 9.2 Critical EPSS 0.4% · p30
Should you act?
Critical and remotely reachable
No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.4%, percentile 30: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 30% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes
payload(npm) >= 3.0.0, < 3.90.0, fixed in 3.90.0;payload(npm) >= 4.0.0-canary.0, < 4.0.0-canary.34, fixed in 4.0.0-canary.34. Check your lockfile, including transitive dependencies.
What it is
Payload is a free and open source headless content management system. In versions after 3.0.0 and before 3.90.0, a custom field option that maps a field to a reserved authentication claim name can place unintended values in the authentication token issued at login. This issue is fixed in version 3.90.0.
From the GitHub advisory
Impact
Under certain field configurations, Payload could include unintended values in the authentication token issued at login.
You are affected if:
- You use an affected Payload version and have configured a custom field option that maps a field to a reserved authentication claim name.
Patches Payload now restricts which field configuration options can influence the contents of the authentication token.
Weakness type: CWE-290, CWE-915.
Product: payload (npm) · Assigned by: GitHub_M · Published: 2026-10-06
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| npm | payload | >= 3.0.0, < 3.90.0 | 3.90.0 |
| npm | payload | >= 4.0.0-canary.0, < 4.0.0-canary.34 | 4.0.0-canary.34 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| payloadcms | payload | >= 3.0.0, < 3.90.0, >= 4.0.0-canary.0, < 4.0.0-canary.34 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 4.0 | 9.2 Critical | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| GitHub | 4.0 | 9.2 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Attack requirements: present (depends on deployment conditions)
- Privileges required: none (no login)
- User interaction: none
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.38% probability of exploitation activity in the next 30 days; percentile 30.
Timeline
- — CVE record published by GitHub_M
- — GitHub-reviewed advisory GHSA-66wr-7vmr-p5jq published (critical)
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-66wr-7vmr-p5jq github.com
- CVE.org record CVE-2026-105863 cve.org
- NVD entry CVE-2026-105863 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com
- github.com github.com