How severe is CVE-2023-1999?

CVE-2023-1999 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2023-1999 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-1999?

CVE-2023-1999 affects Webmproject Libwebp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-1999?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-1999 published?

CVE-2023-1999 was published on 2023-06-20 and last updated on 2026-06-17.

CVE-2023-1999

CVE-2023-1999 is a medium-severity vulnerability in Webmproject Libwebp with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-415.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-415
Affected product: Webmproject Libwebp
Published: 2023-06-20
Last modified: 2026-06-17

Description

There exists a use after free/double free in libwebp. An attacker can use the ApplyFiltersAndEncode() function and loop through to free best.bw and assign best = trial pointer. The second loop will then return 0 because of an Out of memory error in VP8 encoder, the pointer is still assigned to trial and the AddressSanitizer will attempt a double free.

Frequently asked questions

What is CVE-2023-1999?: There exists a use after free/double free in libwebp. An attacker can use the ApplyFiltersAndEncode() function and loop through to free best.bw and assign best = trial pointer. The second loop will then return 0 because of an Out of memory error in VP8 encoder, the pointer is still assigned to trial and the AddressSanitizer will attempt a double free.
How severe is CVE-2023-1999?: CVE-2023-1999 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2023-1999 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-1999?: CVE-2023-1999 affects Webmproject Libwebp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-1999?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-1999 published?: CVE-2023-1999 was published on 2023-06-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:webmproject:libwebp:*:*:*:*:*:*:*:*

More vulnerabilities in Webmproject Libwebp

CVE-2020-36329 — Critical (CVSS 9.8): A flaw was found in libwebp in versions before 1.0.1. A use-after-free was found due to a thread being killed too…
CVE-2020-36328 — Critical (CVSS 9.8): A flaw was found in libwebp in versions before 1.0.1. A heap-based buffer overflow in function WebPDecodeRGBInto is…
CVE-2018-25014 — Critical (CVSS 9.8): A use of uninitialized value was found in libwebp in versions before 1.0.1 in ReadSymbol().
CVE-2018-25011 — Critical (CVSS 9.8): A heap-based buffer overflow was found in libwebp in versions before 1.0.1 in PutLE16().
CVE-2020-36331 — Critical (CVSS 9.1): A flaw was found in libwebp in versions before 1.0.1. An out-of-bounds read was found in function ChunkAssignData. The…
CVE-2020-36330 — Critical (CVSS 9.1): A flaw was found in libwebp in versions before 1.0.1. An out-of-bounds read was found in function ChunkVerifyAndAssign.…

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