The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. From 2.0.0 until 2.16.1 and 3.0.12, automatic response decompression on the HTTP/1.1 path uses ChannelManager.newHttpContentDecompressor() to install Http1ContentDecompressor without a cumulative output-size limit. A hostile or compromised server, or an attacker who can alter a response in transit, can send a small gzip, deflate, or snappy response that expands across chunks until the client exhausts its heap and raises OutOfMemoryError; brotli and zstd are also affected when their optional codecs are present. In versions 3.0.8 through 3.0.10, the HTTP/2 decompressor is also unbounded, so switching protocols does not mitigate the issue on those releases. A limit applied to each decode call is insufficient because the response can be delivered as many small chunks, so the fixed implementation tracks total decompressed bytes for the whole response. This issue is fixed in versions 2.16.1 and 3.0.12.
CVE-2026-85721
This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 71% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 49(Track)EG Risk 49/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 29%
- KEV
- Not listed
Published
September 17, 2026
Last Modified
September 17, 2026
Advisory Details (5)
Auto-updated Sep 17, 2026commit e9f2f7423e0f (AsyncHttpClient/async-http-client)
Patch available: AsyncHttpClient/async-http-client async-http-client-project-2.16.1 (contains commit e9f2f7423e0f)
https://github.com/AsyncHttpClient/async-http-client/commit/e9f2f7423e0f6503f529656f2955a1317e56ba14commit e1871a19972f (AsyncHttpClient/async-http-client)
Patch available: AsyncHttpClient/async-http-client async-http-client-project-3.0.12 (contains commit e1871a19972f)
https://github.com/AsyncHttpClient/async-http-client/commit/e1871a19972fb496be1b8ac6be11d79e22ff2162commit 663a1a917579 (AsyncHttpClient/async-http-client)
Patch available: AsyncHttpClient/async-http-client async-http-client-project-3.0.12 (contains commit 663a1a917579)
https://github.com/AsyncHttpClient/async-http-client/commit/663a1a91757904b22cfe37e2e6049f1f8ea6ae59commit 5ee2841cbf26 (AsyncHttpClient/async-http-client)
Patch available: AsyncHttpClient/async-http-client async-http-client-project-2.16.1 (contains commit 5ee2841cbf26)
https://github.com/AsyncHttpClient/async-http-client/commit/5ee2841cbf268bba4a200578be3938ccfc6cc6d6Unbounded HTTP/1.1 response decompression enables a decompression-bomb denial of service · Advisory · AsyncHttpClient/async-http-client · GitHub
Affected: 3.0.12 on the 3.x line and in 2.16.1 on the 2.x line. The fix counts the decompre
https://github.com/AsyncHttpClient/async-http-client/security/advisories/GHSA-7grg-jcf7-rpmxVendor Advisories for CVE-2026-85721(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
Maven(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| org.asynchttpclient:async-http-client | 3.0.0 ... 3.0.9 (12 versions) | 3.0.12 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 6× in last 7d / 6× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-18 20:44 UTCEG score recompute
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-17 18:26 UTCEG score recompute
- 2026-09-17 17:56 UTCEG score recompute
- 2026-09-17 16:04 UTCEG score recompute
- 2026-09-17 16:04 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-85721?
When was CVE-2026-85721 disclosed?
Is CVE-2026-85721 actively exploited?
What is the CVSS score of CVE-2026-85721?
How do I remediate CVE-2026-85721?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-85721
Is Your Infrastructure Affected by CVE-2026-85721?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.