PatchTheCVECVE-2026-87863: An authenticated HTTPS origin can supply an HSTS `max-age` value that the parser accepts, but time serializati
5
Routine
HIGH n/a
CVE-2026-87863 is a high-severity flaw (CVSS n/a) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
An authenticated HTTPS origin can supply an HSTS `max-age` value that the parser accepts, but time serialization later fails to process. On 64-bit systems, extreme max-age values compute an absolute expiry within standard time integer limits that exceeds calendar time structure bounds. During cache saves, the original HSTS file is truncated before writing a temporary replacement; when serialization fails, the temporary file is deleted, leaving an
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | n/a (High) |
| EPSS exploit chance | 0.3% (top 79%) |
| CISA exploited list | No |
| Published | 2026-10-20 |
| Last modified | 2026-10-22 |
Publisher (CNA): curl
Timeline
- Published CVE record published
- Updated Record last modified
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Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.