Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-9545— exposing HTTP/3 early data

Quick assessment

Affected
curl curl
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

curl是瑞典cURL团队开源的一款用于从服务器传输数据或向服务器传输数据的工具。 curl存在信息泄露漏洞，该漏洞源于在使用HTTP/3服务器传输时，未在证书验证失败前强制执行检查，当使用缓存SSL会话和早期数据功能时，可能泄露敏感信息。

AI Predicted 5.9 Difficulty: Moderate EPSS 0.41% · P33

Affected Version Matrix 17

VendorProduct Version RangeStatus
curl curl 8.11.0< 8.14.2 affected
8.15.0< 8.16.1 affected
8.17.0< 8.20.1 affected
962097b8dd44ed5b9e7984bc1cdffdbdd566857f< 7b9613fa9b1a5e04301a3920eef58e8138dad05e affected
8.20.0 affected
8.19.0 affected
8.18.0 affected
8.17.0 affected
… +9 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-9545

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
exposing HTTP/3 early data
Source: CVE Program / CVE List V5
Vulnerability Description
In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL session (`CURLOPT_SSL_SESSIONID_CACHE` is not disabled) and early data enabled (the `CURLSSLOPT_EARLYDATA` bit is set in `CURLOPT_SSL_OPTIONS`), libcurl might send off the second request's bytes on that new connection *before* enforcing the certificate verification failure. Potentially leaking sensitive information.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
信息暴露
Source: CVE Program / CVE List V5
Vulnerability Title
curl 信息泄露漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
curl是瑞典cURL团队开源的一款用于从服务器传输数据或向服务器传输数据的工具。 curl存在信息泄露漏洞，该漏洞源于在使用HTTP/3服务器传输时，未在证书验证失败前强制执行检查，当使用缓存SSL会话和早期数据功能时，可能泄露敏感信息。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
curl curl 8.11.0 ~ 8.14.2 -
curl curl 962097b8dd44ed5b9e7984bc1cdffdbdd566857f ~ 7b9613fa9b1a5e04301a3920eef58e8138dad05e -
curl curl 8.20.0 -

II. Public POCs for CVE-2026-9545

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-9545

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-9545 (2)

Other References for CVE-2026-9545 (1)

Same Patch Batch · curl · 2026-07-03 · 18 CVEs total

CVE-2026-10536 HTTP/2 stream-dependency tree UAF
CVE-2026-8932 incomplete mTLS config matching in conn reuse
CVE-2026-8458 wrong reuse for different services
CVE-2026-8925 SASL double-free
CVE-2026-8286 wrong STARTTLS connection reuse
CVE-2026-8927 env-set cross-proxy Digest auth state leak
CVE-2026-8926 password leak with netrc and user in URL
CVE-2026-8924 trailing dot domain super cookie
CVE-2026-12064 proto-default skips SSH verification
CVE-2026-11352 QUIC zero-length UDP datagrams busy-loop
CVE-2026-9546 sending old referer
CVE-2026-9080 UAF after pause in socket callback
CVE-2026-9547 SSH improper host validation
CVE-2026-9079 stale proxy password leak
CVE-2026-11564 Native CA trust persist
CVE-2026-11856 cross-origin Digest auth state leak
CVE-2026-11586 WS Auto-PONG memory exhaustion

IV. Related Vulnerabilities

Same product: curl
Same vendor: curl
Same weakness: CWE-200

V. Comments for CVE-2026-9545

No comments yet

Leave a comment