CVE-2023-24535: Parsing invalid messages can panic

This month

HIGH 7.5REMOTEDOWNGRADE

CVE-2023-24535 is a high-severity flaw (CVSS 7.5) affecting protobuf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Parsing invalid messages can panic. Parsing a text-format message which contains a potential number consisting of a minus sign, one or more characters of whitespace, and no further input will cause a panic.

Why this priority

High severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 35%)
CISA exploited list	No
Weakness	CWE-125
Published	2023-06-08
Last modified	2026-06-17

Publisher (CNA): Go Project · Vendor: protobuf

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

Am I affected?

Timeline

2023-06-08 21:15 UTCPublished CVE record published
2026-06-17 05:39 UTCUpdated Record last modified

protobuf protobuf DOWNGRADE

Affected: 1.29.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.29.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.29.0 (Debian / Ubuntu)

apt-cache madison protobuf sudo apt install protobuf=<VERSION_BEFORE_1.29.0> sudo apt-mark hold protobuf

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list protobuf sudo dnf downgrade protobuf-<VERSION_BEFORE_1.29.0> sudo dnf versionlock add protobuf

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-2023-24535?

protobuf: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-24535 being exploited?

CVE-2023-24535 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-2023-24535 affect?

CVE-2023-24535 affects protobuf. Severity is high (CVSS 7.5). Parsing invalid messages can panic. Parsing a text-format message which contains a potential number consisting of a minus sign, one or more characters of whitespace, and no further input will cause a panic.

How urgent is CVE-2023-24535?

Priority 48/100. High severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-0994 HIGH 7.5 UPGRADE A denial-of-service (DoS) vulnerability exists in google.protobuf.json_format.ParseDict() in Python, where the
CVE-2024-7254 HIGH 7.5 UPGRADE UPGRADE Any project that parses untrusted Protocol Buffers data containing an arbitrary number of nested groups / seri
CVE-2024-2410 HIGH 7.6 UPGRADE The JsonToBinaryStream() function is part of the protocol buffers C++ implementation and is used to parse JSON

References

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