CVE-2026-86409
Setting `CURLOPT_AWS_SIGV4` to NULL but does not disable SigV4 authentication, contrary to…
- Risk score
- 58/100
- CVSS
- 8.1 v3.1
- Exploit chance (30 days)
- 0.3%
- Published
- 20 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- Setting CURLOPT_AWS_SIGV4 to NULL but does not disable SigV4 authentication, contrary to expectations and documentation. A subsequent transfer on the same handle still sends an Authorization: AWS4-HMAC-SHA256 header to whatever URL isset next, leaking state information.
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Yellow
- CVSS 8.1 high
- Remotely exploitable without logging in
References
Original description
Setting `CURLOPT_AWS_SIGV4` to NULL but does not disable SigV4 authentication, contrary to expectations and documentation. A subsequent transfer on the same handle still sends an `Authorization: AWS4-HMAC-SHA256` header to whatever URL isset next, leaking state information.
Last activity 20 Oct 2026. Patch Forecast updates every hour.