curl libcurl up to 8.20.0 wrong session

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.3$0-$5k0.75

Summaryinfo

A vulnerability, which was classified as problematic, has been found in curl libcurl. Affected by this issue is some unknown functionality. This manipulation causes wrong session. The identification of this vulnerability is CVE-2026-8458. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability has been found in curl libcurl and classified as problematic. Affected by this vulnerability is an unknown functionality. The manipulation with an unknown input leads to a wrong session vulnerability. The CWE definition for the vulnerability is CWE-488. The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session. As an impact it is known to affect confidentiality. The summary by CVE is:

libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different 'services'. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different services.

The weakness was shared by Muhamad Arga Reksapati. The advisory is shared at curl.se. This vulnerability is known as CVE-2026-8458 since 05/13/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/03/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-41504). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Wrong session
CWE: CWE-488
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

05/13/2026 CVE reserved
07/03/2026 +51 days Advisory disclosed
07/03/2026 +0 days VulDB entry created
07/03/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: curl.se
Researcher: Muhamad Arga Reksapati
Status: Confirmed

CVE: CVE-2026-8458 (🔒)
GCVE (CVE): GCVE-0-2026-8458
GCVE (VulDB): GCVE-100-376069
EUVD: 🔒

Entryinfo

Created: 07/03/2026 08:57
Updated: 07/03/2026 14:19
Changes: 07/03/2026 08:57 (53), 07/03/2026 14:19 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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