Skip to main content
No exploitation reportedFix available

CVE-2026-40490

No exploitation reported by the sources we read.

  • Published2026-04-18
  • Fixed in3.0.9 · 2.14.5
  • WeaknessCWE-200

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. When redirect following is enabled (followRedirect(true)), versions of AsyncHttpClient prior to 3.0.9 and 2.14.5 forward Authorization and Proxy-Authorization headers along with Realm credentials to arbitrary redirect targets regardless of domain, scheme, or port changes. This leaks credentials on cross-domain redirects and HTTPS-to-HTTP downgrades. Additionally, even when stripAuthorizationOnRedirect is set to true, the Realm object containing plaintext credentials is still propagated to the redirect request, causing credential re-generation for Basic and Digest authentication schemes via NettyRequestFactory. An attacker who controls a redirect target (via open redirect, DNS rebinding, or MITM on HTTP) can capture Bearer tokens, Basic auth credentials, or any other Authorization header value. The fix in versions 3.0.9 and 2.14.5 automatically strips Authorization and Proxy-Authorization headers and clears Realm credentials whenever a redirect crosses origin boundaries (different scheme, host, or port) or downgrades from HTTPS to HTTP. For users unable to upgrade, set `(stripAuthorizationOnRedirect(true))` in the client config and avoid using Realm-based authentication with redirect following enabled. Note that `(stripAuthorizationOnRedirect(true))` alone is insufficient on versions prior to 3.0.9 and 2.14.5 because the Realm bypass still re-generates credentials. Alternatively, disable redirect following (`followRedirect(false)`) and handle redirects manually with origin validation.

Timeline

dates in UTC
  1. 2026-04-1802:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-40490?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-40490?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

OSV
async-http-client
BranchAffectedFixed in
3.0≥ 3.0.0.Beta1, < 3.0.93.0.9
2.x≥ 2.0.0, < 2.14.52.14.5

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update async-http-client to 3.0.9 · 2.14.5

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVE recordread 2026-10-23
  • CISA-ADPSSVC decisionnone2026-04-20
  • OpenCVESSVC decisionnone—
  • CNACVSS 3.16.8read 2026-10-23
  • CNAweakness (CWE)CWE-200read 2026-10-23
  • FIRST EPSSEPSS score0.5 %2026-10-23
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
Published
2026-04-18
Last Modified
2026-06-17
NVD status
Deferred

Frequently asked questions

What is CVE-2026-40490?

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. When redirect following is enabled (followRedirect(true)), versions of AsyncHttpClient prior to 3.0.9 and 2.14.5 forward Authorization and Proxy-Authorization headers along with Realm credentials to arbitrary redirect targets regardless of domain, scheme, or port changes. This leaks credentials on cross-domain redirects and HTTPS-to-HTTP downgrades. Additionally, even when stripAuthorizationOnRedirect is set to true, the Realm object containing plaintext credentials is still propagated to the redirect request, causing credential re-generation for Basic and Digest authentication schemes via NettyRequestFactory. An attacker who controls a redirect target (via open redirect, DNS rebinding, or MITM on HTTP) can capture Bearer tokens, Basic auth credentials, or any other Authorization header value. The fix in versions 3.0.9 and 2.14.5 automatically strips Authorization and Proxy-Authorization headers and clears Realm credentials whenever a redirect crosses origin boundaries (different scheme, host, or port) or downgrades from HTTPS to HTTP. For users unable to upgrade, set `(stripAuthorizationOnRedirect(true))` in the client config and avoid using Realm-based authentication with redirect following enabled. Note that `(stripAuthorizationOnRedirect(true))` alone is insufficient on versions prior to 3.0.9 and 2.14.5 because the Realm bypass still re-generates credentials. Alternatively, disable redirect following (`followRedirect(false)`) and handle redirects manually with origin validation.

Is CVE-2026-40490 actively exploited?

Active exploitation of CVE-2026-40490 has not been confirmed. Its EPSS score was 0.5% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-40490?

CVE-2026-40490 has a CVSS v3 base score of 6.8 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this productCISA KEV additions, October 2026Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database