CVE-2026-88038
cookies vulnerable to Set-Cookie attribute injection via unvalidated domain and path options
cookies is a Node.js library for reading and writing HTTP cookies, used by Koa via ctx.cookies. In versions before 0.9.2 the library validates the cookie name and value against character sets that reject the semicolon separator, but the domain and path options are checked only against a permissive RFC 7230 field-content matcher that allows semicolons, and both are written into the Set-Cookie header unescaped. An application that passes untrusted or request-derived data into the domain or path option can therefore inject additional cookie attributes, overriding SameSite, Secure, HttpOnly, or Domain on the cookies the application issues. This is a Set-Cookie attribute injection issue (CWE-74). The issue is fixed in cookies 0.9.2, which validates domain and path against RFC 6265 character sets. As a workaround, keep domain and path application-set rather than derived from untrusted input.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used 4.8
cookies vulnerable to Set-Cookie attribute injection via unvalidated domain and path options
cookies is a Node.js library for reading and writing HTTP cookies, used by Koa via ctx.cookies. In versions before 0.9.2 the library validates the cookie name and value against character sets that reject the semicolon separator, but the domain and path options are checked only against a permissive RFC 7230 field-content matcher that allows semicolons, and both are written into the Set-Cookie header unescaped. An application that passes untrusted or request-derived data into the domain or path option can therefore inject additional cookie attributes, overriding SameSite, Secure, HttpOnly, or Domain on the cookies the application issues. This is a Set-Cookie attribute injection issue (CWE-74). The issue is fixed in cookies 0.9.2, which validates domain and path against RFC 6265 character sets. As a workaround, keep domain and path application-set rather than derived from untrusted input.
- Record
CVE-2026-88038- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-74
- Updated
- 2026-11-02
EUVDEUVD-2026-75398 4.8
cookies is a Node.js library for reading and writing HTTP cookies, used by Koa via ctx.cookies. In versions before 0.9.2 the library validates the cookie name and value against character sets that reject the semicolon separator, but the domain and path options are checked only against a permissive RFC 7230 field-content matcher that allows semicolons, and both are written into the Set-Cookie header unescaped. An application that passes untrusted or request-derived data into the domain or path option can therefore inject additional cookie attributes, overriding SameSite, Secure, HttpOnly, or Domain on the cookies the application issues. This is a Set-Cookie attribute injection issue (CWE-74). The issue is fixed in cookies 0.9.2, which validates domain and path against RFC 6265 character sets. As a workaround, keep domain and path application-set rather than derived from untrusted input.
- Record
EUVD-2026-75398- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
NVD 4.8
cookies is a Node.js library for reading and writing HTTP cookies, used by Koa via ctx.cookies. In versions before 0.9.2 the library validates the cookie name and value against character sets that reject the semicolon separator, but the domain and path options are checked only against a permissive RFC 7230 field-content matcher that allows semicolons, and both are written into the Set-Cookie header unescaped. An application that passes untrusted or request-derived data into the domain or path option can therefore inject additional cookie attributes, overriding SameSite, Secure, HttpOnly, or Domain on the cookies the application issues. This is a Set-Cookie attribute injection issue (CWE-74). The issue is fixed in cookies 0.9.2, which validates domain and path against RFC 6265 character sets. As a workaround, keep domain and path application-set rather than derived from untrusted input.
- Record
CVE-2026-88038- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-74
- Updated
- 2026-11-02
OSV 4.8
cookies vulnerable to Set-Cookie attribute injection via unvalidated domain and path options
cookies is a Node.js library for reading and writing HTTP cookies, used by Koa via ctx.cookies. In versions before 0.9.2 the library validates the cookie name and value against character sets that reject the semicolon separator, but the domain and path options are checked only against a permissive RFC 7230 field-content matcher that allows semicolons, and both are written into the Set-Cookie header unescaped. An application that passes untrusted or request-derived data into the domain or path option can therefore inject additional cookie attributes, overriding SameSite, Secure, HttpOnly, or Domain on the cookies the application issues. This is a Set-Cookie attribute injection issue (CWE-74). The issue is fixed in cookies 0.9.2, which validates domain and path against RFC 6265 character sets. As a workaround, keep domain and path application-set rather than derived from untrusted input.
- Record
CVE-2026-88038- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-74
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-88038 4.8
cookies is a Node.js library for reading and writing HTTP cookies, used by Koa via ctx.cookies. In versions before 0.9.2 the library validates the cookie name and value against character sets that reject the semicolon separator, but the domain and path options are checked only against a permissive RFC 7230 field-content matcher that allows semicolons, and both are written into the Set-Cookie header unescaped. An application that passes untrusted or request-derived data into the domain or path option can therefore inject additional cookie attributes, overriding SameSite, Secure, HttpOnly, or Domain on the cookies the application issues. This is a Set-Cookie attribute injection issue (CWE-74). The issue is fixed in cookies 0.9.2, which validates domain and path against RFC 6265 character sets. As a workaround, keep domain and path application-set rather than derived from untrusted input.
- Record
DEBIAN-CVE-2026-88038- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-88038 4.8
cookies is a Node.js library for reading and writing HTTP cookies, used by Koa via ctx.cookies. In versions before 0.9.2 the library validates the cookie name and value against character sets that reject the semicolon separator, but the domain and path options are checked only against a permissive RFC 7230 field-content matcher that allows semicolons, and both are written into the Set-Cookie header unescaped. An application that passes untrusted or request-derived data into the domain or path option can therefore inject additional cookie attributes, overriding SameSite, Secure, HttpOnly, or Domain on the cookies the application issues. This is a Set-Cookie attribute injection issue (CWE-74). The issue is fixed in cookies 0.9.2, which validates domain and path against RFC 6265 character sets. As a workaround, keep domain and path application-set rather than derived from untrusted input.
- Record
UBUNTU-CVE-2026-88038- CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
node-cookiesDebian:12 | All versions, plus listed versions 0.8.0+~0.7.7-10.9.1+~0.9.2-10.9.2+~0.9.2-1 | None known |
node-cookiesDebian:13 | All versions, plus listed versions 0.8.0+~0.7.7-10.9.1+~0.9.2-10.9.2+~0.9.2-1 | None known |
node-cookiesDebian:14 | before 0.9.2+~0.9.2-1, plus listed versions 0.8.0+~0.7.7-10.9.1+~0.9.2-1 | 0.9.2+~0.9.2-1 |
node-cookiesUbuntu:16.04:LTS | All versions, plus listed versions 0.5.0-1 | None known |
node-cookiesUbuntu:18.04:LTS | All versions, plus listed versions 0.5.0-10.5.0-1ubuntu1 | None known |
node-cookiesUbuntu:20.04:LTS | All versions, plus listed versions 0.5.0-30.8.0-10.8.0-2 | None known |
node-cookiesUbuntu:22.04:LTS | All versions, plus listed versions 0.8.0-20.8.0+~0.7.7-1 | None known |
node-cookiesUbuntu:24.04:LTS | All versions, plus listed versions 0.8.0+~0.7.7-1 | None known |
node-cookiesUbuntu:26.10 | All versions, plus listed versions 0.9.1+~0.9.2-1 | None known |
node-cookiesUbuntu:26.04:LTS | All versions, plus listed versions 0.8.0+~0.7.7-10.9.1+~0.9.2-1 | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-88038 is a medium vulnerability (CVSS 4.8) in Cookies, published September 10, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 16th percentile. Fixed in node-cookies 0.9.2+~0.9.2-1.
References
github.com/pillarjs/cookies/security/advisories/GHSA-x44v-5gxf-r6hf
cna.openjsf.org/security-advisories.html
github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88038.json
nvd.nist.gov/vuln/detail/CVE-2026-88038
security-tracker.debian.org/tracker/CVE-2026-88038
ubuntu.com/security/CVE-2026-88038
cve.org/CVERecord?id=CVE-2026-88038