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Vulnerability record · CVE-2026-54873 · published 29 September 2026

CVE-2026-54873: Openssl allocation without limits vulnerability

OOpenssl · Openssl

Issue summary: QUIC process may keep memory for QUIC packet buffer for much longer period than necessary. Impact summary: Remote peer can exploit this vulnerability by sending maliciously crafted packets, making the local QUIC stack to keep the memory for packet buffers allocated. The time for which the memory remains allocated is entirely under the control of the potentially malicious remote peer. CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: To save copy operation from the packet buffer to the stream reassemble buffer the QUIC stack leaves the stream data on the packet buffer waiting to be copied to a buffer provided by the local receiving application. The QUIC stack releases a reference to the packet buffer only after the data are copied to the application buffer. This design is more efficient for legitimate data transfers but enables an attacker to allocate a lot more memory than actually required by the data kept in the receiving stream buffer. To mitigate the vulnerability, the QUIC stack now calculates and monitors memory overhead for every stream. The memory overhead for a single stream frame is calculated as a difference between the size of the whole packet that carries the stream frame and the size of the stream frame itself. The memory overhead for a single stream frame is added to the total (cumulative) memory overhead QUIC stack keeps for each stream. Once the cumulative memory overhead exceeds 64kB, the QUIC stack moves the stream frame data from the packet buffer to the stream buffer, starting with the next packet received. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.

7.5 CVSS 3.1 High EPSS 0.72% · top 45.5% CWE-770 · Allocation without limits
7.5CVSS 3.1 base score
0.72%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
5References
8 Oct 2026Last modified by NVD

Description

Issue summary: QUIC process may keep memory for QUIC packet buffer for much longer period than necessary. Impact summary: Remote peer can exploit this vulnerability by sending maliciously crafted packets, making the local QUIC stack to keep the memory for packet buffers allocated. The time for which the memory remains allocated is entirely under the control of the potentially malicious remote peer. CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: To save copy operation from the packet buffer to the stream reassemble buffer the QUIC stack leaves the stream data on the packet buffer waiting to be copied to a buffer provided by the local receiving application. The QUIC stack releases a reference to the packet buffer only after the data are copied to the application buffer. This design is more efficient for legitimate data transfers but enables an attacker to allocate a lot more memory than actually required by the data kept in the receiving stream buffer. To mitigate the vulnerability, the QUIC stack now calculates and monitors memory overhead for every stream. The memory overhead for a single stream frame is calculated as a difference between the size of the whole packet that carries the stream frame and the size of the stream frame itself. The memory overhead for a single stream frame is added to the total (cumulative) memory overhead QUIC stack keeps for each stream. Once the cumulative memory overhead exceeds 64kB, the QUIC stack moves the stream frame data from the packet buffer to the stream buffer, starting with the next packet received. FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/openssl/openssl/commit/1f643b8bc735487b500a1f68a7fb3a22d5e38e23 Patch
https://github.com/openssl/openssl/commit/279e7ee1392af98785746788168749491c74bd53 Patch
https://github.com/openssl/openssl/commit/3ea6213e050e938ecbbf8c4eff32bec2736780eb Patch
https://github.com/openssl/openssl/commit/7127fb10888b49711c63128a09e524c0d2d5d0b2 Patch
https://openssl-library.org/news/secadv/20260929.txt Vendor Advisory

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Source: NIST National Vulnerability Database (record CVE-2026-54873), CISA KEV, FIRST EPSS (scores of 2026-11-13). This page is refreshed as NVD updates the record.