CVE-2026-78384 (CVSS 7.5)

Description

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.

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CVSS v3.1 Score

7.5

HIGH

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

EPSS — Exploit Prediction

0.0037

Probability of exploitation

0.31%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-409 CWE-409

References

Other References

https://lists.apache.org/thread.html/xoh63rlxn0m9koft5j4jxrfd0hf81v3q http://www.openwall.com/lists/oss-security/2026/10/09/6

Frequently Asked Questions

What is CVE-2026-78384? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-78384? +

CVE-2026-78384 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0037, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-78384? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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