CVE-2025-47436: Heap-based Buffer Overflow vulnerability in Apache ORC. A vulnerability has been identified in the ORC C++ LZ

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CRITICAL 9.8REMOTEWATCHLISTUPGRADE

CVE-2025-47436 is a critical-severity flaw (CVSS 9.8) affecting orc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Heap-based Buffer Overflow vulnerability in Apache ORC. A vulnerability has been identified in the ORC C++ LZO decompression logic, where specially crafted malformed ORC files can cause the decompressor to allocate a 250-byte buffer but then attempts to copy 295 bytes into it. It causes memory corruption. This issue affects Apache ORC C++ library: through 1.8.8, from 1.9.0 through 1.9.5, from 2.0.0 through 2.0.4, from 2.1.0 through 2.1.1. User

Why this priority

Critical severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-122
Published	2025-05-14
Last modified	2026-06-17

Publisher (CNA): Apache Software Foundation · Vendor: apache

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

Am I affected?

Timeline

2025-05-14 14:15 UTCPublished CVE record published
2026-06-17 09:28 UTCUpdated Record last modified

apache orc UPGRADE

Affected: < 1.8.9 · >= 1.9.0 and < 1.9.6 · >= 2.0.0 and < 2.0.5 · >= 2.1.0 and < 2.1.2

Fixed in: 1.8.9, 1.9.6, 2.0.5, 2.1.2

Safe to downgrade to: a release before 1.9.0

1. Check installed version

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

2. UPGRADE to 1.8.9 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade orc

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 1.9.0 (Debian / Ubuntu)

apt-cache madison orc sudo apt install orc=<VERSION_BEFORE_1.9.0> sudo apt-mark hold orc

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

dnf --showduplicates list orc sudo dnf downgrade orc-<VERSION_BEFORE_1.9.0> sudo dnf versionlock add orc

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-2025-47436?

orc: upgrade to 1.8.9, 1.9.6, 2.0.5, 2.1.2. Exact commands for each OS are on this page.

Is CVE-2025-47436 being exploited?

CVE-2025-47436 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-2025-47436 affect?

CVE-2025-47436 affects orc. Severity is critical (CVSS 9.8). Heap-based Buffer Overflow vulnerability in Apache ORC. A vulnerability has been identified in the ORC C++ LZO decompression logic, where specially crafted malformed ORC files can cause the decompressor to allocate a 250-byte buffer but th

How urgent is CVE-2025-47436?

Priority 56/100. Critical severity; Remotely exploitable, no login, no user action; On your watchlist

Related CVEs

CVE-2024-40897 MEDIUM 6.7 UPGRADE Stack-based buffer overflow vulnerability exists in orcparse.c of ORC versions prior to 0.4.39

References

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