CVE-2026-27700 json
Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo
published 2026-02-25 8 mo ago modified 2026-09-10 1 mo ago also EUVD-2026-8644 , GHSA-xh87-mx6m-69f3
- cvss
- 8.2
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 19%
- public exploits
- 0
- none known
Summary
Hono is a Web application framework that provides support for any JavaScript runtime. In versions 4.12.0 and 4.12.1, when using the AWS Lambda adapter (`hono/aws-lambda`) behind an Application Load Balancer (ALB), the `getConnInfo()` function incorrectly selected the first value from the `X-Forwarded-For` header. Because AWS ALB appends the real client IP address to the end of the `X-Forwarded-For` header, the first value can be attacker-controlled. This could allow IP-based access control mechanisms (such as the `ipRestriction` middleware) to be bypassed. Version 4.12.2 patches the issue.
Patch / fix
- npm hono 4.12.2
- hono hono 4.12.2
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 8 mo ago
Exploit prediction
0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N |
| GitHub | 3.1 | 8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N |
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | hono | >=4.12.0, <4.12.2 |
4.12.2 |
Affected products
- honojs hono
Classification
References
-
github.com
/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7
web, patch
-
github.com
/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3
web, vendor-advisory
-
github.com
/honojs/hono/releases/tag/v4.12.2
web, product, release-notes
-
nvd.nist.gov
/vuln/detail/CVE-2026-27700
advisory
-
github.com
/honojs/hono
package
Sources
- CVE List CVE-2026-27700
- GitHub Advisory GHSA-xh87-mx6m-69f3
- NVD CVE-2026-27700
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.