CVE-2026-78384

HIGH 7.5

Published 2026-10-09 · Last modified 2026-10-15

CompressionUtils.inflate() decompressed attacker-controlled DEFLATE data with no output-size cap. A small (~KB) crafted payload could expand to gigabytes on the heap. Reachable via JWE decryption when zip=DEF (e.g. JoseSessionTokenProvider with RSA-OAEP key wrap) and via SAML redirect/POST binding token inflation — in both cases decompression happens before/independent of trust validation. Fix: Added a configurable maximum inflated-size cap (default 10 MiB, org.apache.cxf.compression-max-inflated-size system property) to CompressionUtils.inflate(); aborts with DataFormatException once exceeded. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

ELEVATED IMPACT

Severe if exploited (CVSS 7.5), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.3%chance of exploitation in 30 days · 19th percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

7.5CVSS 3.1 · HIGH

ConfidentialityHigh
IntegrityNone
AvailabilityNone

What an attacker needs

✓Access: Reachable over the network — no local access needed
✓Privileges: No account or privileges required
✓User interaction: No user interaction needed
✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

github-search Search GitHub for public PoC repos

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-78384/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-78384/poc.json

Affected

Vendors Apache Software Foundation Apache

Products Apache Cxf Cxf

Weakness (CWE)

CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Known Affected Software Configurations

Vendor	Product	Version range
Apache	Cxf	< 3.6.13
Apache	Cxf	≥ 4.0.0 and < 4.1.9
Apache	Cxf	≥ 4.2.0 and < 4.2.4

All CVSS metrics

HIGH 7.5 v3.1 · ADP Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
HIGH 7.5 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

Advisories

https://lists.apache.org/thread.html/xoh63rlxn0m9koft5j4jxrfd0hf81v3q vendor-advisoryIssue TrackingVendor Advisory
http://www.openwall.com/lists/oss-security/2026/10/09/6 Mailing ListThird Party Advisory

Sources: NVD · CVE.org · EPSS