vulnerability / NVI-00018460 / Revision 1
Hono: Cookie helper does not sanitize sameSite and priority, allowing Set-Cookie injection
GitHub lists this reviewed advisory for hono. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
4.3 medium
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
hono
source listed< 4.12.21
### Summary The `serialize()` function in `hono/cookie` validates `domain` and `path` options against characters that corrupt `Set-Cookie` header syntax (`;`, `\r`, `\n`), but does not apply the same validation to `sameSite` and `priority`. An application that passes user-controlled input into either option may produce a `Set-Cookie` response header containing attacker-chosen additional attributes. ### Details When constructing a `Set-Cookie` header value, `serialize()` appends the `sameSite` and `priority` option values directly into the output string after a presentation-only transformation (capitalizing the first character). Although the TypeScript type signature constrains these options to specific string literals, that constraint is not enforced at runtime; any string value, including one containing `;` or line-feed characters, passes through unchanged. The validation guard that rejects `;`, `\r`, and `\n` from `domain` and `path` is not applied to `sameSite` or `priority`. An application that passes a request-derived value to either option therefore provides an injection point into the header line. This issue arises when an application passes user-controlled input to the
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-3hrh-pfw6-9m5x ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.