CVE-2021-29506: GraphHopper is an open-source Java routing engine

This month

MEDIUM 6.5UPGRADE

CVE-2021-29506 is a medium-severity flaw (CVSS 6.5) affecting graphhopper. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

GraphHopper is an open-source Java routing engine. In GrassHopper from version 2.0 and before version 2.4, there is a regular expression injection vulnerability that may lead to Denial of Service. This has been patched in 2.4 and 3.0 See this pull request for the fix: https://github.com/graphhopper/graphhopper/pull/2304

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.4% (top 27%)
CISA exploited list	No
Weakness	CWE-400
Published	2021-05-13
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: graphhopper

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-05-13 19:15 UTCPublished CVE record published
2026-06-17 03:47 UTCUpdated Record last modified

graphhopper graphhopper UPGRADE

Affected: >= 2.0 and < 2.4

Fixed in: 2.4

Safe to downgrade to: a release before 2.0

1. Check installed version

apt-cache policy graphhopper || rpm -q graphhopper || graphhopper --version

2. UPGRADE to 2.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade graphhopper

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade graphhopper

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.0 (Debian / Ubuntu)

apt-cache madison graphhopper sudo apt install graphhopper=<VERSION_BEFORE_2.0> sudo apt-mark hold graphhopper

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list graphhopper sudo dnf downgrade graphhopper-<VERSION_BEFORE_2.0> sudo dnf versionlock add graphhopper

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-29506?

graphhopper: upgrade to 2.4. Exact commands for each OS are on this page.

Is CVE-2021-29506 being exploited?

CVE-2021-29506 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-29506 affect?

CVE-2021-29506 affects graphhopper. Severity is medium (CVSS 6.5). GraphHopper is an open-source Java routing engine. In GrassHopper from version 2.0 and before version 2.4, there is a regular expression injection vulnerability that may lead to Denial of Service. This has been patched in 2.4 and 3.0 See th

How urgent is CVE-2021-29506?

Priority 41/100. No elevated risk signals yet.

Software pages

Java vulnerabilities · GitHub vulnerabilities

Related CVEs

CVE-2021-23408 MEDIUM 5.4 UPGRADE This affects the package com.graphhopper:graphhopper-web-bundle before 3.2, from 4.0-pre1 and before 4.0

References

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