CVE-2026-87863

HIGH
MEDIUM Priority: 0.02 BB Relevance: 66/100
Published: 2026-10-20 Modified: 2026-10-30 First seen: 2026-10-29 Status: active

Attack Surface

Network No Auth No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: High
PR: None
UI: None
S: Unchanged
C: High
I: High
A: High

Description

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.

Weakness Classification (1)

Affected Software (28)

VendorProductVersion
curl curl 8.22.0
curl curl 8.21.0
curl curl 8.20.0
curl curl 8.19.0
curl curl 8.18.0
curl curl 8.17.0
curl curl 8.16.0
curl curl 8.15.0
curl curl 8.14.1
curl curl 8.14.0
curl curl 8.13.0
curl curl 8.12.1
curl curl 8.12.0
curl curl 8.11.1
curl curl 8.11.0
curl curl 8.10.1
curl curl 8.10.0
curl curl 8.9.1
curl curl 8.9.0
curl curl 8.8.0
curl curl 8.7.1
curl curl 8.7.0
curl curl 8.6.0
curl curl 8.5.0
curl curl 8.4.0
curl curl 8.3.0
curl curl 8.2.1
curl curl 8.2.0

Bug Bounty Relevance

66 / 100
✓ Network accessible
✓ No authentication
✓ No user interaction

CVSS Score

8.1 / 10.0 v3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploitation Probability

0.27%
Raw Score 0.002660
Percentile 18.6%
Date 2026-10-30

EPSS Trend

2026-10-30
0.00266
2026-10-29
0.00266
2026-10-28
0.00266

Intelligence Sources

mitre ref →
nvd ref →