vulnerability / NVI-00012984 / Revision 2
Jawn: Uncontrolled nesting depth in JSON parser
GitHub lists this reviewed advisory for org.typelevel:jawn-parser_2.12, org.typelevel:jawn-parser_2.13, org.typelevel:jawn-parser_3. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.5 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
0.615%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.49512. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
org.typelevel:jawn-parser_2.12
source listed<= 1.6.0
The Jawn parser before 1.6.1 is vulnerable to a denial of service attack via untrusted input. ### Impact A remote attacker who can submit JSON to any jawn-backed parse method can exhaust JVM heap and trigger `java.lang.OutOfMemoryError`. This is treated by Scala as a fatal error and not typically handled by `scala.util.Try` or `cats.effect.IO`. ### Patches Version `1.6.1` introduces a configurable nesting-depth limit (`Parser#maxDepth`, default `4096`). Inputs deeper than the limit fail with a recoverable `ParseException` instead of exhausting heap. Users who require deeper nesting may override `maxDepth` on a `Parser` subclass. ### Workarounds - Enforce an input size limit small enough that the resulting context stack cannot exhaust heap, (e.g. http4s `EntityLimiter`). - Pre-scan untrusted input and reject documents whose maximum delimiter nesting exceeds a threshold before handing them to jawn.
org.typelevel:jawn-parser_2.13
source listed<= 1.6.0
The Jawn parser before 1.6.1 is vulnerable to a denial of service attack via untrusted input. ### Impact A remote attacker who can submit JSON to any jawn-backed parse method can exhaust JVM heap and trigger `java.lang.OutOfMemoryError`. This is treated by Scala as a fatal error and not typically handled by `scala.util.Try` or `cats.effect.IO`. ### Patches Version `1.6.1` introduces a configurable nesting-depth limit (`Parser#maxDepth`, default `4096`). Inputs deeper than the limit fail with a recoverable `ParseException` instead of exhausting heap. Users who require deeper nesting may override `maxDepth` on a `Parser` subclass. ### Workarounds - Enforce an input size limit small enough that the resulting context stack cannot exhaust heap, (e.g. http4s `EntityLimiter`). - Pre-scan untrusted input and reject documents whose maximum delimiter nesting exceeds a threshold before handing them to jawn.
org.typelevel:jawn-parser_3
source listed<= 1.6.0
The Jawn parser before 1.6.1 is vulnerable to a denial of service attack via untrusted input. ### Impact A remote attacker who can submit JSON to any jawn-backed parse method can exhaust JVM heap and trigger `java.lang.OutOfMemoryError`. This is treated by Scala as a fatal error and not typically handled by `scala.util.Try` or `cats.effect.IO`. ### Patches Version `1.6.1` introduces a configurable nesting-depth limit (`Parser#maxDepth`, default `4096`). Inputs deeper than the limit fail with a recoverable `ParseException` instead of exhausting heap. Users who require deeper nesting may override `maxDepth` on a `Parser` subclass. ### Workarounds - Enforce an input size limit small enough that the resulting context stack cannot exhaust heap, (e.g. http4s `EntityLimiter`). - Pre-scan untrusted input and reject documents whose maximum delimiter nesting exceeds a threshold before handing them to jawn.
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-cc4v-rvgp-2pf3 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-59990 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.