THREAT OPS › Threat News › [NVD] CVE-2026-6253 (MEDIUM 5.9) — curl might erroneously pass on credentials for a first proxy to a second
proxy.
This can happen when the following conditions are true:
1. curl is setup to use specific different proxies for different URL schemes
2. the first proxy needs credentials
3. the second proxy uses no
[NVD] CVE-2026-6253 (MEDIUM 5.9) — curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the following conditions are true: 1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no
CVE-2026-6253 CVSS: 5.9 MEDIUM Published: 2026-05-13T13:01:56.570
curl might erroneously pass on credentials for a first proxy to a second proxy.
This can happen when the following conditions are true:
1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. while using the first proxy (using say
MITRE ATT&CK techniques
- CredentialsT1589.001
Indicators of compromise
- CVE-2026-6253cve
- http://`url
- https://`url
Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-6253