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QUIC: Unbounded RETIRE_CONNECTION_ID Backlog

Issue summary: A malicious remote peer may flood the local QUIC stack with NEW_CONNECTION_ID frames by avoiding a limit check on how many connection IDs the remote QUIC stack can use. Impact summary: The local QUIC stack sends a RETIRE_CONN_ID frame for every NEW_CONNECTION_ID frame it receives. The RETIRE_CONN_ID frame is dispatched via the Control Frame Queue (CFQ). If the remote peer also withholds ACKs, then it can force the local stack to allocate ~400MB (depending on ACK delay). CWE: CWE-770: Allocation of Resources Without Limits or Throttling Description: RFC 9000 sections 5.1.1 and 5.1.2 [1] describe the mechanism by which a remote peer can notify the local QUIC stack to change the destination connection ID (a.k.a. CID) the local stack uses to identify the connection at the remote peer. Each CID is associated with a sequence number. The sequence number is transmitted in NEW_CONNECTION_ID and RETIRE_CONNECTION_ID frames to identify the CID which is being either associated with a connection or retired. The remote peer sends a NEW_CONNECTION_ID frame to let the local stack know a new CID is being associated with an existing connection. The NEW_CONNECTION_ID frame carries the new CID, its sequence number, and the retire-prior-to number. The retire-prior-to identifies existing CIDs that are to be retired. The local QUIC stack must send a RETIRE_CONNECTION_ID for every destination CID whose sequence number is less than retire-prior-to. The CID becomes retired after the loc

Structured advisory · Revision 1Original source
Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-84784

OpenSSL

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
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Prerequisites
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Related CVEs
CVE-2026-84784

Source reference: /cveMetadata/cveId

Publisher severity

No explicit severity was provided.

Event
#3839 · Revision 1
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advisoryOfficial CVE List

Use-After-Free in X.509 Extension Cache Under Concurrent Use

Issue summary: The first concurrent use of the same X.509 certificate by several threads may cause its cached extension data to be freed while another thread is still using it. Impact summary: A remote, unauthenticated peer could crash a multi-threaded TLS client, or a multi-threaded TLS server that requests client certificates, if the first certificate chains built to the same trusted CA certificate are built by several connections at the same time. This is a use-after-free read, which is likely to crash the process, resulting in a Denial of Service. CWE: CWE-416: Use After Free Description: OpenSSL caches the decoded values of a certificate's X.509v3 extensions inside the X509 object the first time they are needed. In OpenSSL 4.0 this cache is built in two phases: the extension values are computed while holding a read lock on the certificate, and the results are then installed into the certificate under a write lock. Because a read lock does not exclude other readers, several threads can compute the cache for the same certificate at the same time. Each thread that subsequently acquires the write lock installs its own results and frees the values installed by the thread before it, even though that earlier thread has already marked the cache as complete and may have returned pointers into it to its caller. A caller still using those pointers then reads freed memory. Any certificate shared between threads is exposed the first time its extensions are decoded. In TLS the certifi

Structured advisory · Revision 1Original source
Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-84783

OpenSSL

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record
Related CVEs
CVE-2026-84783

Source reference: /cveMetadata/cveId

Publisher severity

No explicit severity was provided.

Event
#3838 · Revision 1
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advisoryOfficial CVE List

DTLS Retransmits Handshake Messages From a Stale Buffer Offset

Issue summary: The DTLS retransmission logic does not correctly handle a handshake message write that is suspended part-way through. The retransmitted message can be read past the message buffer and the retransmission overwrites the internal state the suspended write needs to resume correctly. Impact summary: The retransmitted message can disclose a heap memory to the peer as plaintext handshake data or cause a crash and a Denial of Service when the read reaches an unmapped memory region. CWE: CWE-125: Out-of-bounds Read Description: DTLS handshake messages can be written out in multiple fragments, and a write can suspend mid-message (returning WANT_WRITE) if the underlying transport temporarily cannot accept more data. While such a write is suspended, the DTLS retransmission timer may independently fire and ask the retransmission logic to resend an earlier, already-acknowledged-as-sent message from its retransmit queue. The retransmission logic reused the same internal buffer and position tracking as the message that was still being written, without resetting the position back to the start of the message being retransmitted. As a result the retransmission was read starting from wherever the suspended write had left off, producing a mislabelled message whose body was leftover bytes from the other, larger message still in flight - content that was never meant to be sent at that point, and which could run past the end of the allocated buffer. Separately, even when the retransmi

Structured advisory · Revision 1Original source
Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-84782

OpenSSL

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record
Related CVEs
CVE-2026-84782

Source reference: /cveMetadata/cveId

Publisher severity

No explicit severity was provided.

Event
#3837 · Revision 1
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advisoryOfficial CVE List

Timing Side-Channel in SM2 Signature Generation

Issue summary: SM2 signature generation uses non-constant-time arithmetic on secret values, forming a timing side-channel. Impact summary: An attacker able to measure SM2 signing times may learn information about the per-signature secret nonce, which over many signatures can, via a lattice / Hidden Number Problem attack, lead to recovery of the private key. CWE: CWE-208: Observable Timing Discrepancy Description: SM2 signature generation computes the signature value using variable-time BIGNUM operations on the secret nonce and the private key, so the time taken to produce an SM2 signature depends on these secret values, forming a timing side-channel. Applications performing SM2 signature generation are affected on all platforms. FIPS Impact: no SM2 is not a FIPS algorithm.

Structured advisory · Revision 1Original source
Evidence and details

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-77696

OpenSSL

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record
Related CVEs
CVE-2026-77696

Source reference: /cveMetadata/cveId

Publisher severity

No explicit severity was provided.

Event
#3834 · Revision 1
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