CVE-2026-5052: Vault’s PKI engine’s ACME validation did not reject local targets when issuing http-01 and tls-alpn-01 challen

Routine

MEDIUM 5.3REMOTEUPGRADE

CVE-2026-5052 is a medium-severity flaw (CVSS 5.3) affecting vault. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Vault’s PKI engine’s ACME validation did not reject local targets when issuing http-01 and tls-alpn-01 challenges. This may lead to these requests being sent to local network targets, potentially leading to information disclosure. Fixed in Vault Community Edition 2.0.0 and Vault Enterprise 2.0.0, 1.21.5, 1.20.10, and 1.19.16.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 72%)
CISA exploited list	No
Weakness	CWE-918
Published	2026-04-17
Last modified	2026-10-26

Publisher (CNA): HashiCorp Inc. · Vendor: hashicorp

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-17 04:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

hashicorp vault UPGRADE

Affected: >= 1.14.0 and < 1.19.16 · >= 1.14.0 and < 2.0.0 · >= 1.20.0 and < 1.20.10 · >= 1.21.0 and < 1.21.5

Fixed in: 1.19.16, 1.20.10, 1.21.5, 2.0.0

Safe to downgrade to: a release before 1.14.0

1. Check installed version

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

2. UPGRADE to 1.19.16 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade vault

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 1.14.0 (Debian / Ubuntu)

apt-cache madison vault sudo apt install vault=<VERSION_BEFORE_1.14.0> sudo apt-mark hold vault

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

dnf --showduplicates list vault sudo dnf downgrade vault-<VERSION_BEFORE_1.14.0> sudo dnf versionlock add vault

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-2026-5052?

vault: upgrade to 1.19.16, 1.20.10, 1.21.5, 2.0.0. Exact commands for each OS are on this page.

Is CVE-2026-5052 being exploited?

CVE-2026-5052 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-2026-5052 affect?

CVE-2026-5052 affects vault. Severity is medium (CVSS 5.3). Vault’s PKI engine’s ACME validation did not reject local targets when issuing http-01 and tls-alpn-01 challenges. This may lead to these requests being sent to local network targets, potentially leading to information disclosure. Fixed in

How urgent is CVE-2026-5052?

Priority 31/100. Remotely exploitable, no login, no user action

Software pages

HashiCorp Vault vulnerabilities

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References

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