VulnerabilityPublished 21 Oct 2026Updated 30 Oct 2026

CVE-2026-79704: Out-of-bounds Read Vulnerability Exists

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Authoritative record:CVE-2026-79704· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade to 1.18.0 soon.

Data as of 30 Oct 2026, 21:05 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CISA-ADP	CVSS 3.1	7.5

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.18.0

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-xp33-gmw5-5ggc

What to do

Upgrade Apache bRPC and apache/brpc to 1.18.0.

Affected software

Product	Affected	Fixed in
Apache bRPCapache/brpc	Affected >=1.11.0 <1.18.0	Fixed in 1.18.0
GitHubapache/brpc`pkg:github/apache/brpc`Other threats	Affected >=1.11.0 <1.18.0	Fixed in 1.18.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade Apache bRPC to version 1.18.0, which includes a fix that rejects responses with mismatched extra_stream_ids counts, causing the RPC to fail cleanly. Alternatively, apply the patch available at https://github.com/apache/brpc/pull/3485. No other mitigation is required as the fix prevents partial processing of malformed responses.

Description

An out-of-bounds read vulnerability exists in the streaming RPC client of Apache bRPC versions 1.11.0 through 1.17.0. The flaw occurs when a client creates multiple streams in a single RPC and the server response contains fewer extra_stream_ids than expected, leading to an out-of-bounds read. This can cause the client process to crash (denial of service) or leak unintended memory contents. The issue is fixed in version 1.18.0.

Impact

A malicious or compromised server or an attacker on the network path can exploit this vulnerability by sending a malformed StreamSettings response with fewer extra_stream_ids than expected. This triggers an out-of-bounds read in the client, potentially causing a denial of service via client crash or unintended memory disclosure. There is no impact on confidentiality or integrity beyond memory leakage and service disruption.

Summary

Apache bRPC versions 1.11.0 through 1.17.0 have an out-of-bounds read vulnerability in the streaming RPC client. When a client creates multiple streams in one RPC, it expects the server to return exactly one extra_stream_id per additional stream. The client indexes the returned identifiers without validating the list size, so a malicious or compromised server can send fewer extra_stream_ids than expected, causing an out-of-bounds read. This may crash the client or leak memory. The fix in version 1.18.0 enforces strict validation of the extra_stream_ids count, rejecting malformed responses and preventing partial processing.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 21:05 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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