CVE-2026-40542
What it is
Missing critical step in authentication in Apache HttpClient 5.6 allows an attacker to cause the client to accept SCRAM-SHA-256 authentication without proper mutual authentication verification. Users are recommended to upgrade to version 5.6.1, which fixes this issue.
At a glance
- Exploitability
- Can be exploited over the network without logging in. Limited direct impact.
- Exploit odds
- 0.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.5% in the next 30 days (EPSS).
- Severity: 7.3 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.5% · EPSS, next 30 days
- Weakness
- CWE-304
- Record status
- Modified
Affected
- Apache Httpclient 5.6
Attack profile CVSS 3.1 · 7.3
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-40542.md and follow it. Check whether this project is affected by CVE-2026-40542. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
References
- https://lists.apache.org/thread/tfmgv86xr0z1y096vs3z0y315t1v3o97
- http://www.openwall.com/lists/oss-security/2026/04/22/5
- https://access.redhat.com/errata/RHSA-2026:60239
- https://access.redhat.com/errata/RHSA-2026:60246
- https://access.redhat.com/errata/RHSA-2026:60247
- https://access.redhat.com/errata/RHSA-2026:60248
- https://access.redhat.com/errata/RHSA-2026:60249
- https://access.redhat.com/errata/RHSA-2026:60250
- https://access.redhat.com/errata/RHSA-2026:60251
- https://access.redhat.com/errata/RHSA-2026:60252
- https://access.redhat.com/errata/RHSA-2026:60254
- https://access.redhat.com/errata/RHSA-2026:60256
- https://access.redhat.com/errata/RHSA-2026:60259
- https://access.redhat.com/security/cve/CVE-2026-40542
- https://bugzilla.redhat.com/show_bug.cgi?id=2460518
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40542.json