CVE-2026-87863: high-severity vulnerability in curl
HSTS response erases persisted entries
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.1epss 0.8%
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 empty or partial cache. Because the save error is silently ignored during
cleanup, curl exits successfully despite the data loss.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
curl · curlRelated CVEs — curl
In the same product, most dangerous first.