CVE-2023-34188
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers.
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers. By sending a single attack payload over TCP, an attacker can cause an infinite loop in which the server continuously reparses that payload, and does not respond to any other requests.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers. By sending a single attack payload over TCP, an attacker can cause an infinite loop in which the server continuously reparses that payload, and does not respond to any other requests.
- Record
CVE-2023-34188- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1284
- Updated
- 2026-11-02
CVE List No score
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers. By sending a single attack payload over TCP, an attacker can cause an infinite loop in which the server continuously reparses that payload, and does not respond to any other requests.
- Record
CVE-2023-34188- Weakness
- CWE-1284
- Updated
- 2026-11-02
EUVDEUVD-2023-38288
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers. By sending a single attack payload over TCP, an attacker can cause an infinite loop in which the server continuously reparses that payload, and does not respond to any other requests.
- Record
EUVD-2023-38288- CVSS
- 0.0 None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-pcw9-xw4x-jgj3
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers.
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers.
- Record
GHSA-pcw9-xw4x-jgj3- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-1284
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2023-34188
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers. By sending a single attack payload over TCP, an attacker can cause an infinite loop in which the server continuously reparses that payload, and does not respond to any other requests.
- Record
DEBIAN-CVE-2023-34188- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2023-34188
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers. By sending a single attack payload over TCP, an attacker can cause an infinite loop in which the server continuously reparses that payload, and does not respond to any other requests.
- Record
UBUNTU-CVE-2023-34188- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSV No score
The HTTP server in Mongoose before 7.10 accepts requests containing negative Content-Length headers. By sending a single attack payload over TCP, an attacker can cause an infinite loop in which the server continuously reparses that payload, and does not respond to any other requests.
- Record
CVE-2023-34188- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
swupdateDebian:12 |
All versions, plus listed versions 2022.12+dfsg-42022.12+dfsg-4+deb12u12022.12+dfsg-4+deb12u1~bpo11+12022.12+dfsg-4+deb12u22022.12+dfsg-4+deb12u3 Show 45 moreShow less2023.05+dfsg-12023.05+dfsg-22023.05+dfsg-2~bpo12+12023.05+dfsg-32023.05+dfsg-42023.05+dfsg-52023.05+dfsg-5~bpo12+12023.12+dfsg-12023.12+dfsg-1~bpo12+12023.12.1+dfsg-12023.12.1+dfsg-1~bpo12+12023.12.1+dfsg-22023.12.1+dfsg-2~bpo12+12024.05+dfsg-12024.05.2+dfsg-12024.05.2+dfsg-22024.05.2+dfsg-2~bpo12+12024.12+dfsg-12024.12+dfsg-22024.12+dfsg-2~bpo12+12024.12.1+dfsg-12024.12.1+dfsg-1~bpo12+12024.12.1+dfsg-22024.12.1+dfsg-32024.12.1+dfsg-3~bpo12+12025.05+dfsg-12025.05+dfsg-22025.05+dfsg-2~bpo13+12025.05+dfsg-32025.05+dfsg-3~bpo13+12025.12+dfsg-12025.12+dfsg-102025.12+dfsg-10~bpo13+12025.12+dfsg-10~bpo13+22025.12+dfsg-22025.12+dfsg-2~bpo13+12025.12+dfsg-32025.12+dfsg-42025.12+dfsg-52025.12+dfsg-62025.12+dfsg-72025.12+dfsg-7~bpo13+12025.12+dfsg-82025.12+dfsg-92026.05+dfsg-1 |
None known |
swupdateDebian:13 |
before 2024.12+dfsg-1 | 2024.12+dfsg-1 |
swupdateDebian:14 |
before 2024.12+dfsg-1 | 2024.12+dfsg-1 |
swupdateUbuntu:22.04:LTS |
All versions, plus listed versions 2020.11-22021.04-1.12021.04-22021.04-2build12021.11-1 |
None known |
swupdateUbuntu:24.04:LTS |
All versions, plus listed versions 2023.05+dfsg-32023.05+dfsg-42023.05+dfsg-4build12023.05+dfsg-52023.12+dfsg-12023.12.1+dfsg-1ubuntu12023.12.1+dfsg-1ubuntu42023.12.1+dfsg-1ubuntu5 |
None known |
mongooseUbuntu:26.10 |
All versions, plus listed versions 7.21+ds-17.21+ds-27.22+ds-17.23+ds-1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-34188 is a high vulnerability (CVSS 7.5) in Cesanta Mongoose, published June 23, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.00%, the 63rd percentile. Fixed in swupdate 2024.12+dfsg-1.
References
github.com/cesanta/mongoose/commit/4663090a8fb036146dfe77718cff612b0101cb0f
blog.narfindustries.com/blog/narf-discovers-critical-vulnerabilities-in-cesanta-mongoose-http-server
security.netapp.com/advisory/ntap-20250228-0001
nvd.nist.gov/vuln/detail/CVE-2023-34188
Left out here: 9 versions. The JSON record has them.