CVE-2026-43628: llama.cpp builds b3978 through b9058 contain an integer underflow and out-of-bounds read vulnerability in the

Routine

HIGH 7.8UPGRADE

CVE-2026-43628 is a high-severity flaw (CVSS 7.8) affecting llama.cpp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

llama.cpp builds b3978 through b9058 contain an integer underflow and out-of-bounds read vulnerability in the DRY sampler that allows unauthenticated attackers to trigger a heap buffer underflow by sending a crafted HTTP request with dry_allowed_length set to INT32_MIN to the /v1/completions or /v1/chat/completions endpoints. Attackers can exploit this vulnerability to crash the server with SIGSEGV causing denial of service for all connected user

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 86%)
CISA exploited list	No
Weakness	CWE-125, CWE-191
Published	2026-08-06
Last modified	2026-10-23

Publisher (CNA): VulnCheck · Vendor: ggml

Last updated 2026-10-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-08-06 22:17 UTCPublished CVE record published
2026-10-23 21:10 UTCUpdated Record last modified

ggml llama.cpp UPGRADE

Affected: >= b3978 and <= b9058

Fixed in: newer than b9058

Safe to downgrade to: a release before b3978

1. Check installed version

apt-cache policy llama.cpp || rpm -q llama.cpp || llama.cpp --version

2. UPGRADE to newer than b9058 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade llama.cpp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade llama.cpp

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 b3978 (Debian / Ubuntu)

apt-cache madison llama.cpp sudo apt install llama.cpp=<VERSION_BEFORE_b3978> sudo apt-mark hold llama.cpp

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

dnf --showduplicates list llama.cpp sudo dnf downgrade llama.cpp-<VERSION_BEFORE_b3978> sudo dnf versionlock add llama.cpp

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-2026-43628?

llama.cpp: upgrade to newer than b9058. Exact commands for each OS are on this page.

Is CVE-2026-43628 being exploited?

CVE-2026-43628 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-2026-43628 affect?

CVE-2026-43628 affects llama.cpp. Severity is high (CVSS 7.8). llama.cpp builds b3978 through b9058 contain an integer underflow and out-of-bounds read vulnerability in the DRY sampler that allows unauthenticated attackers to trigger a heap buffer underflow by sending a crafted HTTP request with dry_al

How urgent is CVE-2026-43628?

Priority 31/100. High severity

Software pages

OpenAI and LLM tools vulnerabilities

Related CVEs

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CVE-2026-70638 HIGH 7.8 UPGRADE llama.cpp builds b1886 through b7445 contain an integer overflow vulnerability in the LLaMA-Android JNI wrappe
CVE-2026-70639 MEDIUM 5.5 UPGRADE llama.cpp builds b1886 through b7445 contain a null pointer dereference vulnerability in the LLaMA-Android JNI
CVE-2026-43629 HIGH 8.1 UPGRADE llama.cpp builds b4882 through b9058 contain a heap buffer overflow vulnerability in the KV cache state restor
CVE-2026-43631 HIGH 8.1 UPGRADE llama.cpp builds b7492 through the latest b9060 contains a use-after-free vulnerability in the vocab pointer o

References

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