Description
Jawn is an open source JSON parser. Prior to 1.7.0, Jawn's AsyncParser can perform quadratic work when a single JSON token is delivered across many small chunks because each absorb call rescans the incomplete token from the start. A remote attacker who controls untrusted JSON input and its chunk sizes can exhaust CPU resources and cause denial of service in applications using AsyncParser. This issue is fixed in version 1.7.0.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| typelevel | jawn | < 1.7.0 | — |
| org.typelevel | jawn-parser_2.12 | < 1.7.0 | — |
| org.typelevel | jawn-parser_2.13 | < 1.7.0 | — |
| org.typelevel | jawn-parser_3 | < 1.7.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | jawn | No fix yet | — |
| Debian 13 | jawn | No fix yet | — |
| Debian 12 | jawn | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | jawn | No fix yet | — |
| Ubuntu 26.04 LTS | jawn | No fix yet | — |
| Ubuntu 24.04 LTS | jawn | No fix yet | — |
| Ubuntu 22.04 LTS | jawn | No fix yet | — |
| Ubuntu 20.04 LTS | jawn | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | jawn | 0.14.1-150200.3.6.1 | SUSE-SU-2026:4407-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.typelevel:jawn-parser_2.12 | < 1.7.0 | 1.7.0 | GHSA-w4cm-gvhj-cgw6 |
| Maven | org.typelevel:jawn-parser_2.13 | < 1.7.0 | 1.7.0 | GHSA-w4cm-gvhj-cgw6 |
| Maven | org.typelevel:jawn-parser_3 | < 1.7.0 | 1.7.0 | GHSA-w4cm-gvhj-cgw6 |
Advisories 1
- SUSE-SU-2026:4407-1 Security update for jawn SUSE / openSUSE Security Updates · Oct 1, 2026