CVE-2023-29942: llvm-project commit a0138390 was discovered to contain a segmentation fault via the component mlir::Type::isa<

Q: How urgent is CVE-2023-29942?

Priority 22/100. No elevated risk signals yet.

Routine

MEDIUM 5.5DOWNGRADE

CVE-2023-29942 is a medium-severity flaw (CVSS 5.5) affecting llvm. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

llvm-project commit a0138390 was discovered to contain a segmentation fault via the component mlir::Type::isa<mlir::LLVM::LLVMVoidType.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 87%)
CISA exploited list	No
Weakness	CWE-125
Published	2023-05-05
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: llvm

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

Am I affected?

Timeline

2023-05-05 15:15 UTCPublished CVE record published
2026-06-17 05:51 UTCUpdated Record last modified

llvm llvm DOWNGRADE

Affected: 2023-01-12

Fixed in: no fixed release known

Safe to downgrade to: a release before 2023-01-12

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2023-01-12 (Debian / Ubuntu)

apt-cache madison llvm sudo apt install llvm=<VERSION_BEFORE_2023-01-12> sudo apt-mark hold llvm

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

dnf --showduplicates list llvm sudo dnf downgrade llvm-<VERSION_BEFORE_2023-01-12> sudo dnf versionlock add llvm

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-2023-29942?

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

Is CVE-2023-29942 being exploited?

CVE-2023-29942 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-2023-29942 affect?

CVE-2023-29942 affects llvm. Severity is medium (CVSS 5.5). llvm-project commit a0138390 was discovered to contain a segmentation fault via the component mlir::Type::isa<mlir::LLVM::LLVMVoidType.

How urgent is CVE-2023-29942?

Priority 22/100. No elevated risk signals yet.

Related CVEs

CVE-2023-29941 MEDIUM 5.5 DOWNGRADE llvm-project commit a0138390 was discovered to contain a segmentation fault via the component matchAndRewriteS
CVE-2023-29939 MEDIUM 5.5 DOWNGRADE llvm-project commit a0138390 was discovered to contain a segmentation fault via the component mlir::spirv::Tar
CVE-2023-29935 MEDIUM 5.5 DOWNGRADE llvm-project commit a0138390 was discovered to contain an assertion failure at !replacements.count(op) && "ope
CVE-2023-29934 MEDIUM 5.5 DOWNGRADE llvm-project commit 6c01b5c was discovered to contain a segmentation fault via the component mlir::Type::getDi
CVE-2023-29933 MEDIUM 5.5 DOWNGRADE llvm-project commit bd456297 was discovered to contain a segmentation fault via the component mlir::Block::get

References

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