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Fencer Vulns
medium 6.5

CVE-2026-77421 json

JLine: ReDoS in Nano Editor Regex Search Mode

published 2026-09-23 46 d ago modified 2026-09-30 39 d ago also GHSA-ph9c-7hw9-vhhw , EUVD-2026-85522

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

JLine is a Java library for handling console input. From 3.0.0 until 3.30.15 and 4.3.1, the JLine built-in nano editor's regex search mode passes a user-controlled search term from doSearch(String text) in builtins/src/main/java/org/jline/builtins/Nano.java to Java's backtracking regular expression engine without a timeout or backtracking bound. A nested-quantifier expression evaluated against non-matching buffer content can consume excessive CPU and indefinitely block the editor session thread, and remote multi-user deployments can lose a worker thread for each affected session. This issue is fixed in versions 3.30.15 and 4.3.1.

Patch / fix

  • maven org.jline:jline-builtins 3.30.15, 4.3.1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-77421 updated cvss 5.7

org.jline/jline-builtins: JLine: Denial of Service in Nano Editor Regex Search

  • Red Hat AMQ Broker 7 jline-reader, jline-builtins 3.30.8.redhat-00001
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Fuse 7 jline-reader, jline-builtins 3.30.8.redhat-00001
    affected: workaround, no fix available, no fix planned “Out of support scope”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-spark-operator-rhel9, rhoai/odh-th-torch-cpu-py312-rhel9, rhoai/odh-th-torch-cuda-py312-rhel9, rhoai/odh-th06-cpu-torch210-py312-rhel9, rhoai/odh-th06-cpu-torch291-py312-rhel9, rhoai/odh-th06-rocm64-torch291-py312-rhel9, +2 more
    affected: workaround, no fix available “Fix deferred”
  • Red Hat OpenStack Platform 13 (Queens) opendaylight
    affected: workaround, no fix planned “Out of support scope”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
46 d ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven org.jline:jline-builtins
>=4.0.0, <4.3.1
>=3.0.0, <3.30.15
4.3.1
3.30.15

Affected products

  • jline jline3

Classification

Weakness
  • CWE-1333 Inefficient Regular Expression Complexity

References

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.