CVE-2026-87863
HSTS response erases persisted entries
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.
INFO
Published Date :
Oct. 20, 2026, 9:17 p.m.
Last Modified :
Oct. 20, 2026, 9:17 p.m.
Remotely Exploit :
No
Source :
2499f714-1537-4658-8207-48ae4bb9eae9
Solution
- Update the affected software to the latest version.
- Apply vendor patches for HSTS parsing errors.
- Review HSTS configuration for extreme values.
- Ensure cache integrity after updates.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-87863.
| URL | Resource |
|---|---|
| https://curl.se/docs/CVE-2026-87863.html | |
| https://curl.se/docs/CVE-2026-87863.json | |
| https://hackerone.com/reports/3972373 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-87863 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-87863
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-87863 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-87863 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 2499f714-1537-4658-8207-48ae4bb9eae9
Oct. 20, 2026
Action Type Old Value New Value Added 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/87xxx/CVE-2026-87863.json">CVE-2026-87863</a> Added Reference https://curl.se/docs/CVE-2026-87863.html Added Reference https://curl.se/docs/CVE-2026-87863.json Added Reference https://hackerone.com/reports/3972373