CVE-2026-115473
Mongoose: Heap OOB reads and null-byte bypass in mg_path_is_sane (util.c)
Mongoose is an embedded web server and network library. Prior to 7.22, mg_path_is_sane in src/util.c read path.buf[1] without first requiring path.len to be at least two and read s[2] when only two bytes remained. Unauthenticated remote requests reaching mg_http_upload or mg_http_serve_dir with the affected short path shapes could therefore trigger one-byte heap out-of-bounds reads. On bare-metal or RTOS targets without memory protection, the adjacent byte could be exposed or influence whether a path was accepted, and instrumented builds could crash. This issue is fixed in version 7.22.
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
- Low
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
6.5
Mongoose: Heap OOB reads and null-byte bypass in mg_path_is_sane (util.c)
Mongoose is an embedded web server and network library. Prior to 7.22, mg_path_is_sane in src/util.c read path.buf[1] without first requiring path.len to be at least two and read s[2] when only two bytes remained. Unauthenticated remote requests reaching mg_http_upload or mg_http_serve_dir with the affected short path shapes could therefore trigger one-byte heap out-of-bounds reads. On bare-metal or RTOS targets without memory protection, the adjacent byte could be exposed or influence whether a path was accepted, and instrumented builds could crash. This issue is fixed in version 7.22.
- Record
CVE-2026-115473- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L - Weakness
- CWE-125, CWE-158
- Updated
- 2026-11-05
EUVDEUVD-2026-117180
6.5
Mongoose is an embedded web server and network library. Prior to 7.22, mg_path_is_sane in src/util.c read path.buf[1] without first requiring path.len to be at least two and read s[2] when only two bytes remained. Unauthenticated remote requests reaching mg_http_upload or mg_http_serve_dir with the affected short path shapes could therefore trigger one-byte heap out-of-bounds reads. On bare-metal or RTOS targets without memory protection, the adjacent byte could be exposed or influence whether a path was accepted, and instrumented builds could crash. This issue is fixed in version 7.22.
- Record
EUVD-2026-117180- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L - Updated
- 2026-11-05
NVD
6.5
Mongoose is an embedded web server and network library. Prior to 7.22, mg_path_is_sane in src/util.c read path.buf[1] without first requiring path.len to be at least two and read s[2] when only two bytes remained. Unauthenticated remote requests reaching mg_http_upload or mg_http_serve_dir with the affected short path shapes could therefore trigger one-byte heap out-of-bounds reads. On bare-metal or RTOS targets without memory protection, the adjacent byte could be exposed or influence whether a path was accepted, and instrumented builds could crash. This issue is fixed in version 7.22.
- Record
CVE-2026-115473- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L - Weakness
- CWE-125, CWE-158
- Updated
- 2026-11-05
OSV
6.5
Mongoose: Heap OOB reads and null-byte bypass in mg_path_is_sane (util.c)
Mongoose is an embedded web server and network library. Prior to 7.22, mg_path_is_sane in src/util.c read path.buf[1] without first requiring path.len to be at least two and read s[2] when only two bytes remained. Unauthenticated remote requests reaching mg_http_upload or mg_http_serve_dir with the affected short path shapes could therefore trigger one-byte heap out-of-bounds reads. On bare-metal or RTOS targets without memory protection, the adjacent byte could be exposed or influence whether a path was accepted, and instrumented builds could crash. This issue is fixed in version 7.22.
- Record
CVE-2026-115473- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L - Weakness
- CWE-125, CWE-158
- Updated
- 2026-11-07
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| references | CVE List, EUVD | |
| aliases, references | OSV | |
| aliases, products, published | EUVD, NVD | |
| first indexed | CVE List |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-115473 is a medium vulnerability (CVSS 6.5) in Automattic Mongoose, published November 4, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.26%, the 18th percentile. No source names a fixed version.
References
github.com/cesanta/mongoose/security/advisories/GHSA-cjmx-764f-286c
github.com/cesanta/mongoose/commit/b55de8b151d1466a3e41d1f854f22eeb6faa23dc
github.com/cesanta/mongoose/releases/tag/7.22
github.com/CVEProject/cvelistV5/tree/main/cves/2026/115xxx/CVE-2026-115473.json
nvd.nist.gov/vuln/detail/CVE-2026-115473