Hash collision in typelevel jawn

published 2022-01-05 4 y ago modified 2026-06-17 4 mo ago also GHSA-vc89-hccf-rq55 , EUVD-2022-0702

cvss: 5.9; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 57%
public exploits: 0; none known

Jawn is an open source JSON parser. Extenders of the `org.typelevel.jawn.SimpleFacade` and `org.typelevel.jawn.MutableFacade` who don't override `objectContext()` are vulnerable to a hash collision attack which may result in a denial of service. Most applications do not implement these traits directly, but inherit from a library. `jawn-parser-1.3.1` fixes this issue and users are advised to upgrade. For users unable to upgrade override `objectContext()` to use a collision-safe collection.

Patch / fix

fixed in 4 distros 1 links 2

maven org.typelevel:jawn-parser_2.12 1.3.2
maven org.typelevel:jawn-parser_2.13 1.3.2
maven org.typelevel:jawn-parser_3 1.3.2
typelevel jawn 1.3.2

jawn Package Hub 15 SP2 0.14.1-bp152.2.3.1
jawn openSUSE Leap 15.3 0.14.1-3.3.1
jawn Package Hub 15 SP3, openSUSE Leap 15.3 0.14.1-bp153.2.3.1

opensuse advisories openSUSE-SU-2022:0045-1 openSUSE-SU-2022:0106-1 openSUSE-SU-2022:0011-1

github.com/typelevel/jawn#390 pull request
github.com/typelevel/jawn/security/advisories/GHSA-vc89-hccf-rq55 advisory

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 18 mo ago (2025-04-22)

Exploit prediction

0.82% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/typelevel/jawn/pull/390 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
maven	org.typelevel:jawn-parser_0.25	all versions	no fix listed
maven	org.typelevel:jawn-parserg	all versions	no fix listed
maven	org.typelevel:jawn-parser_0.27	all versions	no fix listed
maven	org.typelevel:jawn-parser_2.10	all versions	no fix listed
maven	org.typelevel:jawn-parser_2.11	all versions	no fix listed
maven	org.typelevel:jawn-parser_2.12	<1.3.2	1.3.2
maven	org.typelevel:jawn-parser_2.13	<1.3.2	1.3.2
maven	org.typelevel:jawn-parser_2.13.0-M5	all versions	no fix listed
maven	org.typelevel:jawn-parser_2.13.0-RC1	all versions	no fix listed
maven	org.typelevel:jawn-parser_2.13.0-RC2	all versions	no fix listed
maven	org.typelevel:jawn-parser_2.13.0-RC3	all versions	no fix listed
maven	org.typelevel:jawn-parser_3	<1.3.2	1.3.2
maven	org.typelevel:jawn-parser_3.0.0-M1	all versions	no fix listed
maven	org.typelevel:jawn-parser_3.0.0-M2	all versions	no fix listed
maven	org.typelevel:jawn-parser_3.0.0-M3	all versions	no fix listed
maven	org.typelevel:jawn-parser_3.0.0-RC1	all versions	no fix listed
maven	org.typelevel:jawn-parser_3.0.0-RC2	all versions	no fix listed
maven	org.typelevel:jawn-parser_3.0.0-RC3	all versions	no fix listed

Affected products

typelevel jawn

Classification

Weakness

CWE-400 Uncontrolled Resource Consumption
CWE-326 Inadequate Encryption Strength

References

github.com /typelevel/jawn/pull/390
web, exploit, issue-tracking, patch, third-party-advisory
github.com /typelevel/jawn/security/advisories/GHSA-vc89-hccf-rq55
web, patch, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2022-21653
advisory
github.com /typelevel/jawn
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary