CVE-2026-9545General(haxx / curl)

LOWCVSS 7.5 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD 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uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate.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.

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0.0/ 10 priority

Sources & remediation

Patch / fix

https://curl.se/docs/CVE-2026-9545.html

Exploit / PoC references

Vendor / third-party advisories

https://curl.se/docs/CVE-2026-9545.json

Weakness type (CWE)

CWE-200

Priority

LOW

Exploitation

NONE

PoC

YES

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

curl

Threat summary

1 mentions across 1 observed day

What's happening

Technical details provided in 1 signal
General: 1 classified signal
1 total mentions across 1 day

Affected systems

Vendors

haxx

Products

curl

Deep dive

Activity timeline1 mentions / 1d

Signal classification1 categories

General

1100.0%

Referenced assets2 URLs

By indicator

Full discourse1 post

Vulmon Vulnerability Feed@VulmonFeeds46d
General
CVE-2026-9545 SSL Session Reuse Information Disclosure in libcurl HTTP/3 Connect... https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-9545 Vulnerability Alert Subscriptions: https://alerts.vulmon.com/?utm_source=twitter&utm_medium=social&utm_campaign=2102281&utm_content=1
Post summary
The post references CVE-2026-9545, noting an information‑disclosure flaw in libcurl’s SSL session reuse handling for HTTP/3, but provides no PoC, exploit code, patch details, or evidence of active exploitation.
00000116
4.1K followersView on X

CPE platform detail1 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

1 of 1 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	haxx	curl	-	-	-

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