proxy credentials leak over redirect-to proxy (curl curl)

CVE-2026-6253
MEDIUM 5.9

At a glance

Source
NVD
EPSS
EPSS 0.72 % · percentile 54 ()
State
PUBLISHED
Published
Updated
Assigner
curl
NVD status
Modified

Description

curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the following conditions are true: 1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. while using the first proxy (using say `http://`), curl is asked to follow a redirect to a URL using another scheme (say `https://`), accessed using a second, different, proxy

Weaknesses (CWE)

  • CWE-522 — Insufficiently Protected Credentials

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HCISA-ADP
CVSS 3.1MEDIUM 5.9CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HNVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
curl · curlaffected 7.14.1 < 8.14.2 ; affected 8.15.0 < 8.16.1 ; affected 8.17.0 < 8.20.0
curl · curlaffected 3b60bb725913ce7339aefef0a14b12df4c24db60 < 188c2f166a20fa97c2325b2da7d0e5cecc13725f
curl · curlaffected 8.19.0 ; affected 8.18.0 ; affected 8.17.0 ; affected 8.16.0 ; affected 8.15.0 ; affected 8.14.1

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD