Vulnerability

CVE-2023-27536

Low· 5.9CVSS5.9EPSS0%

.rules3/5

curl/libcurl: GSS delegation too eager connection reuse

libcurl would reuse a previously created connection even when the GSS delegation (`CURLOPT_GSSAPI_DELEGATION`) option had been changed that could have changed the user's permissions in a second transfer. libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. However, this GSS delegation setting was left out from the configuration match checks, making them match too easily, affecting krb5/kerberos/negotiate/GSSAPI transfers.

Threat signal

59/100

Elevated

Severity

low

CVSS

5.9

EPSS

Active

CVSS

v3.1via NVDOpen in FIRST calculator →

5.9/ 10MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack VectorNetworkExploitable remotely over the internet — no local access needed.
Attack ComplexityHighRequires conditions outside attacker's control (race, brute-force, configuration
Privileges RequiredNoneUnauthenticated — no credentials needed.
User InteractionNoneFully automated — no victim action needed.
ScopeUnchangedImpact contained to the vulnerable component.
Confidentiality ImpactHighTotal disclosure of sensitive data.
Integrity ImpactNoneNo integrity impact.
Availability ImpactNoneNo availability impact.

EPSS

Exploit prediction · 30-day horizonFIRST.org →

0.01%

probability of exploitation in next 30 days

higher than 1% of all CVEs

3-day trend↑ 0pp

Low exploitation likelihood — defer if no other signals fire.

Vendor VEX

No VEX statements published for CVE-2023-27536. Vendors publish VEX (Vulnerability Exploitability eXchange) to assert per-product whether a CVE is actually exploitable in their distribution.

SSVCDefer

No exploitation, limited impact or prevalence

exploitation: none
automatable: no
impact: partial
mission: support

Lifecycle

2023-03-20Published
2023-06-07Vendor advisory · amazon-linuxALAS2-2023-2070 — ALAS2-2023-2070 (medium): curl
2026-04-25Last modified2 sources

Entity graph

2 nodes · 1 edges · click to pivot

CVEActorVendor advisoryIOCNews

Vendor advisories

amazon-linuxALAS2-2023-2070ALAS2-2023-2070 (medium): curl

References

No source-event history recorded yet. New revisions will appear here as ingestors re-fetch this CVE.